Northern Trust (NTRS) 424B5Prospectus supplement for primary offering

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-219591

The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell nor do they seek an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED APRIL 28, 2020

PROSPECTUS SUPPLEMENT

(To Prospectus dated July 31, 2017)

$                

Northern Trust Corporation

% Senior Notes due

The            % Senior Notes due                (the “notes”) will bear interest at an annual rate of            %, payable semi-annually in arrears on                and                of each year, beginning on                , 2020. We may redeem the notes, in whole or in part, on or after the date that is                months prior to their maturity date at a redemption price equal to 100% of the principal amount of the notes to be redeemed plus accrued and unpaid interest to, but excluding, the redemption date.

The notes will be unsecured and rank equally with all of our other existing and future senior debt.

See “Risk Factors” beginning on pageS-4 of this prospectus supplement and beginning on page 3 of the accompanying prospectus to read about important factors you should consider before buying the notes.

None of the U.S. Securities and Exchange Commission, any state securities commission or any other regulatory body has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The initial public offering price set forth above does not include accrued interest, if any. Interest on the notes will accrue from                , 2020 and must be paid by the purchasers if the notes are delivered after that date.

The notes will not be listed on any securities exchange. Currently, there is no public market for the notes. The notes are not deposits or other obligations of a bank and are not insured by the Federal Deposit Insurance Corporation or other governmental agency.

The underwriters expect to deliver the notes through the facilities of The Depository Trust Company and its participants, including Euroclear Bank SA/NV and Clearstream Banking S.A., against payment in New York, New York on                , 2020.

Joint Book-Running Managers

The date of this prospectus supplement is                , 2020.

Table of Contents

PROSPECTUS SUPPLEMENT

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ABOUT THIS PROSPECTUS SUPPLEMENT

This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of the notes we are offering and certain other matters relating to us and our financial condition. The second part, the accompanying prospectus, gives more general information about securities we may offer from time to time, some of which does not apply to the notes we are offering. Generally, when we refer to this prospectus, we are referring to both parts of this document combined. To the extent any information in this prospectus supplement, including the description of the notes, differs from the information in the accompanying prospectus, you should rely on the information in this prospectus supplement.

You should rely only on the information contained in this document or to which this document refers you, or other offering materials filed by us with the U.S. Securities and Exchange Commission (the “SEC”). We have not authorized anyone, and we have not authorized the underwriters to authorize anyone, to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein is accurate only as of their respective dates, regardless of the time of delivery of this prospectus supplement or any sale of the notes. Our business, financial condition, results of operations and prospects may have changed since those dates.

The notes are offered globally for sale in those jurisdictions in the United States, Canada, Europe, Asia and elsewhere where it is lawful to make such offers. See “Underwriting.”

The distribution of this prospectus supplement and the accompanying prospectus and the offering of the notes in certain jurisdictions may be restricted by law. Persons who obtain possession of this prospectus supplement and the accompanying prospectus should inform themselves about and observe any such restrictions. This prospectus supplement and the accompanying prospectus do not constitute, and may not be used in connection with, an offer or solicitation by anyone in any jurisdiction in which such offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to any person to whom it is unlawful to make such offer or solicitation. See “Underwriting.”

References herein to “$” and “dollars” are to the currency of the United States. Unless otherwise indicated or the context otherwise requires, references in this prospectus supplement to “Northern Trust,” “we,” “us” and “our” are to Northern Trust Corporation and its consolidated subsidiaries. References to “the Corporation” are to Northern Trust Corporation. References to “the Bank” are to The Northern Trust Company.

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FORWARD-LOOKING STATEMENTS

This prospectus supplement and the accompanying prospectus, including the documents incorporated by reference herein and therein, and other statements that Northern Trust may make, may contain forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are typically identified by words or phrases such as “believe,” “expect,” “anticipate,” “intend,” “estimate,” “project,” “likely,” “plan,” “goal,” “target,” “strategy,” and similar expressions or future or conditional verbs such as “may,” “will,” “should,” “would,” and “could.” Forward-looking statements include statements, other than those related to historical facts, that relate to our financial results and outlook; capital adequacy; dividend policy and share repurchase program; accounting estimates and assumptions; credit quality including allowance levels; future pension plan contributions; effective tax rate; anticipated expense levels; contingent liabilities; acquisitions, strategies; market and industry trends; and expectations regarding the impact of accounting pronouncements and legislation. These statements are based on our current beliefs and expectations of future events or future results and involve risks and uncertainties that are difficult to predict and subject to change. These statements are also based on assumptions about many important factors, including:

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Actual results may differ materially from those expressed or implied by forward-looking statements. You should carefully read the risk factors described in “Risk Factors” herein and in the documents incorporated by reference in this prospectus supplement and the accompanying prospectus for a description of certain risks that could, among other things, cause our actual results to differ from these forward-looking statements.

The information contained in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein is current only as of the date of that information. All forward-looking statements included in such documents are based upon information available at the time such statements are made, and we assume no obligation to update any forward-looking statements.

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RISK FACTORS

In deciding whether to invest in the notes, you should consider carefully the following factors that could materially adversely affect our operating results and financial condition and the value of your investment in the notes. Although we have tried to discuss key factors, please be aware that other risks may prove to be important and may arise in the future. New risks may emerge at any time, and we cannot predict those risks or estimate the extent to which they may affect our financial performance or the value of your investment in the notes. You should also consider the information included in our Annual Report on Form10-K for the fiscal year ended December 31, 2019 and our Quarterly Report on Form10-Q for the quarterly period ended March 31, 2020, as well as any subsequent reports on Form8-K we may file. Each of the risks described below could result in a decrease in the value of the notes and your investment therein.

We are a holding company, and as a result we are dependent on dividends from our subsidiaries, including the Bank, to meet our obligations, including with respect to the notes.

We are a holding company that conducts substantially all of our operations through the Bank, our investment in which is our principal asset and source of income. We are a legal entity separate and distinct from the Bank and our other subsidiaries and, therefore, rely primarily on dividends from these subsidiaries to meet our obligations, including with respect to the notes, and to provide funds for payment of dividends to our stockholders, to the extent declared by our board of directors. There are various regulatory restrictions on the ability of the Bank to pay dividends or make other payments to us. For example, federal banking laws regulate the amount of dividends that may be paid by the Bank without prior approval of the Federal Reserve Board. In addition, contractual or other restrictions may also limit our subsidiaries’ abilities to pay dividends or make payments to us. For these reasons, we may not have access to any assets or cash flow of our subsidiaries to make payments on the notes.

The notes are structurally subordinated to the debt of our subsidiaries, which means that creditors (including depositors) of our subsidiaries generally will be paid from those subsidiaries’ assets before holders of the notes would have any claims to those assets.

Because we are a holding company, our rights and the rights of our creditors, including the holders of the notes, to a share of the assets of any subsidiary upon the liquidation or recapitalization of the subsidiary will be subject to the prior claims of the subsidiary’s creditors (including, in the case of the Bank and our other banking subsidiaries, their depositors), except to the extent that we may ourselves be a creditor with recognized claims against the subsidiary. Accordingly, the notes will be effectively subordinated to all existing and future liabilities of our subsidiaries. At March 31, 2020, the Bank and our other subsidiaries’ total liabilities, including deposits and other liabilities, that would effectively rank senior to the notes were approximately $147.0 billion.

There may not be any trading market for the notes; many factors affect the trading market and value of the notes.

Upon issuance, the notes will not have an established trading market. We do not intend to list the notes on any securities exchange. We cannot assure you that a trading market for the notes will ever develop or be maintained if developed. In addition to our creditworthiness, many factors affect the trading market for, and trading value of, the notes. These factors include:

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You should also be aware that there may be a limited number of buyers when you decide to sell your notes. This may affect the price you receive for your notes or your ability to sell your notes at all.

A downgrade, suspension or withdrawal of any rating assigned by a rating agency to us or our securities, including the notes, could cause the liquidity or market value of the notes to decline significantly.

Real or anticipated changes in the credit ratings assigned to the notes or our credit ratings generally could affect the market value of the notes. Credit ratings are not a recommendation to buy, sell or hold any security, and may be revised or withdrawn at any time by the issuing organization in its sole discretion. In addition, credit rating agencies continually review their ratings for the companies that they follow, including us. The credit rating agencies also evaluate the financial services industry as a whole and may change their credit rating for us and our securities, including the notes, based on their overall view of our industry.

A downgrade, withdrawal, or the announcement of a possible downgrade or withdrawal in the ratings assigned to the notes, us or our other securities, or any perceived decrease in our creditworthiness, could cause the market value of the notes to decline significantly.

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USE OF PROCEEDS

The net proceeds from the offering of the notes, after deducting the underwriting discount and estimated offering expenses payable by us, are expected to be approximately $                . We intend to use the net proceeds from the sale of the notes for general corporate purposes.

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CAPITALIZATION

The following table shows our capitalization and short-term indebtedness at March 31, 2020 (1) on a consolidated basis and (2) on a consolidated basis as adjusted to reflect the issuance and sale of the notes. This table should be read in conjunction with our consolidated financial statements and related notes for the three months ended March 31, 2020, incorporated by reference in this prospectus supplement and the accompanying prospectus. See “Where You Can Find More Information” in the accompanying prospectus.

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DESCRIPTION OF THE NOTES

Please read the following information concerning the notes in conjunction with the statements under “Description of the Debt Securities” in the accompanying prospectus, which the following information supplements and, if there are any inconsistencies, supersedes. The following description is not complete. The notes will be issued under the Indenture, dated as of May 8, 2017, between us and The Bank of New York Mellon Trust Company, N.A., as trustee, as amended and supplemented by the Fourth Supplemental Indenture, to be entered into between us and the trustee (together, the “Indenture”). The Indenture has been qualified under the Trust Indenture Act of 1939, as amended.

Maturity

The notes will mature on                ,                . At maturity, the amounts due and payable on the notes will be 100% of their principal amount outstanding, together with accrued and unpaid interest thereon to the maturity date. If the maturity falls on a day that is not a business day, the payment of principal and interest will be made on the next succeeding business day with the same force and effect as if made at maturity, and no interest on such payment will accrue for the period from and after such maturity.

Interest Rate and Interest Payment Dates

The notes will bear interest from, and including,                , 2020 at the annual rate of                %, and we will pay accrued interest semi-annually in arrears on                and                of each year (or if any of these days is not a business day, on the next business day, and no interest will accrue as a result of that postponement), beginning on                , 2020.

Interest payments will be made to the persons or entities in whose names the notes are registered at the close of business on                and                (whether or not a business day), as the case may be, immediately preceding the relevant interest payment date. The amount of interest payable for any interest period will be computed on the basis of a360-day year consisting of twelve30-day months.

Redemption

On or after                ,                (the date that is                months prior to their maturity date), the notes will be redeemable, at our option, in whole or in part at any time and from time to time, at a redemption price equal to 100% of the principal amount of the notes to be redeemed plus accrued and unpaid interest thereon to, but excluding, the redemption date.

Notice of any redemption will be sent not less than 30 days nor more than 60 days before the redemption date to each holder of the notes to be redeemed. Unless we default in payment of the redemption price, on and after the redemption date, interest will cease to accrue on the notes or portions thereof called for redemption.

Ranking

The notes will be unsecured and rank equally with all of our other existing and future senior debt.

Sale of the Bank

The indenture for the notes provides that, so long as the notes remain outstanding, we will not:

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This restriction does not apply to a disposition or stock issuance:

Forms and Denominations

The notes will be issued as one or more fully registered global securities in the name of a nominee of The Depository Trust Company (“DTC”) and will be available only in book-entry form. See “Description of the Debt Securities—Global Securities” in the accompanying prospectus. The notes are available for purchase in minimum denominations of $2,000 and in integral multiples of $1,000 in excess thereof.

Additional Notes

The notes are initially limited in aggregate principal amount to $            . We may, without the consent of the holders of the notes offered by this prospectus supplement, create and issue additional notes ranking equally with the notes offered by this prospectus supplement in all respects, including having the same CUSIP number, so that such additional notes would be consolidated and form a single series with the notes offered by this prospectus supplement and would have the same terms as to status, redemption or otherwise as the notes offered hereby, except for public offering price and issue date. Additional notes may not be fungible with the notes for U.S. federal income tax purposes.

Listing

The notes will not be listed on any securities exchange. Currently, there is no public market for the notes.

Governing Law

The Indenture and the notes shall be governed by and construed in accordance with the laws of the State of New York.

Depositary

Upon issuance, the notes will be represented by one or more fully registered global notes. Each global note will be deposited with, or on behalf of, DTC or any successor thereto, as depositary, and registered in the name of Cede & Co. (DTC’s partnership nominee).

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U.S. FEDERAL INCOME TAX CONSIDERATIONS FORNON-U.S. HOLDERS

The following discussion is a summary of U.S. federal income tax considerations generally applicable to the acquisition, ownership and disposition of the notes as of the date hereof tonon-U.S. holders (as defined below) that acquire notes for cash at their original issue price pursuant to this offering. This summary is based on the Internal Revenue Code of 1986, as amended (the “Code”), Treasury Regulations, judicial decisions, published positions of the IRS, and other applicable authorities, all as in effect as of the date hereof and all of which are subject to change or differing interpretations (possibly with retroactive effect). This summary does not cover all aspects of U.S. federal income taxation that may be relevant to anon-U.S. holder in light of thenon-U.S. holder’s particular circumstances. In addition, this summary does not describe the impact of the U.S. federal income tax consequences applicable to anon-U.S. holder that is subject to special treatment under the Code, including, without limitation, certain former citizens and former long-term residents of the United States, a “controlled foreign corporation,” a “passive foreign investment company,” a partnership or other “pass through” entity or an investor in any such entity, atax-exempt organization, a bank or other financial institution, or a broker, dealer or trader in securities. In addition, this discussion does not address the consequences of the alternative minimum tax, taxpayers subject to special accounting rules under Section 451(b) of the Code or any state, local ornon-U.S. tax consequences or any tax consequences other than U.S. federal income tax consequences. This summary deals only with persons who hold the notes as capital assets within the meaning of the Code (generally, property held for investment). No IRS ruling has been or will be sought regarding any matter discussed herein. Holders are urged to consult their tax advisors as to the particular U.S. federal tax consequences to them of the acquisition, ownership and disposition of notes, as well as the effects of state, local andnon-U.S. tax laws.

For purposes of this summary, a“non-U.S. holder” means a beneficial owner of a note (as determined for U.S. federal income tax purposes) that is not, and is not treated as, a citizen or individual resident of the United States, a corporation (or other entity treated as a corporation for U.S. federal income tax purposes) created or organized in the United States or under the laws of the United States or any political subdivision thereof or the District of Columbia, an estate the income of which is subject to U.S. federal income taxation regardless of its source, or a trust if (i) a court within the United States is able to exercise primary supervision over the administration of the trust and one or more U.S. persons have the authority to control all substantial decisions of the trust, or (ii) the trust has a valid election in effect to be treated as a U.S. person.

If a partnership (including any entity treated as a partnership for U.S. federal income tax purposes) is a holder of a note, the U.S. federal income tax treatment of a partner in the partnership generally will depend on the status of the partner and the activities of such partnership. Partners and partnerships should consult their tax advisors as to the particular U.S. federal income tax consequences applicable to them.

Interest.Subject to the discussion of backup withholding below, anon-U.S. holder generally will not be subject to U.S. federal income or withholding tax on interest paid on a note if the interest is not effectively connected with anon-U.S. holder’s conduct of a U.S. trade or business (or, in the case of certain tax treaties, is not attributable to a permanent establishment or fixed base within the United States), provided that thenon-U.S. holder:

Anon-U.S. holder that cannot satisfy the above requirements generally will be exempt from U.S. federal withholding tax with respect to interest paid on the notes if the holder establishes that such interest is not subject to withholding tax because it is effectively connected with thenon-U.S. holder’s conduct of a trade or business in

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the United States (generally, by providing an IRS FormW-8ECI). However, to the extent that such interest is effectively connected with thenon-U.S. holder’s conduct of a trade or business (and, in the case of certain tax treaties, is attributable to a permanent establishment or fixed base within the United States), thenon-U.S. holder will be subject to U.S. federal income tax on a net basis and, if it is a foreign corporation, may be subject to a 30% U.S. branch profits tax (or lower applicable treaty rate). In addition, under certain income tax treaties, the U.S. withholding rate on interest payments may be reduced or eliminated, provided thenon-U.S. holder complies with the applicable certification requirements (generally, by providing an IRS FormW-8BEN, IRS FormW-8BEN-E or other applicable form or successor form). If anon-U.S. holder does not satisfy the requirements described above, and does not establish that the interest is effectively connected with thenon-U.S. holder’s conduct of a trade or business in the United States, thenon-U.S. holder will generally be subject to U.S. withholding tax, currently imposed at a rate of 30%.

Disposition.Subject to the discussion below regarding information reporting and backup withholding, anon-U.S. holder generally will not be subject to U.S. federal income taxation with respect to gain realized on the sale, exchange or other disposition of a note, unless:

If thenon-U.S. holder holds the note in connection with the conduct of a U.S. trade or business (and, in the case of certain tax treaties, the gain is attributable to a permanent establishment or fixed base within the United States maintained by thenon-U.S. holder), the first exception applies, and thenon-U.S. holder generally will be subject to U.S. federal income tax on a net basis and, if it is a foreign corporation, may be subject to a 30% U.S. branch profits tax (or lower applicable treaty rate). If thenon-U.S. holder is an individual that is present in the United States for 183 days or more during the taxable year in which gain is realized (and certain other conditions are met), the second exception applies, and thenon-U.S. holder generally will be subject to U.S. federal income tax at a rate of 30% (or at a reduced rate under an applicable income tax treaty) on the amount by which capital gains allocable to U.S. sources (including gains from the sale, exchange, retirement or other disposition of the notes) exceed capital losses allocable to U.S. sources.

Information reporting and backup withholding.Anon-U.S. holder not subject to U.S. income tax may nonetheless be subject to backup withholding and information reporting with respect to interest paid or accrued on a note, and with respect to amounts realized on the disposition of a note, unless thenon-U.S. holder provides the withholding agent with the applicable IRS FormW-8 or otherwise establishes an exemption.Non-U.S. holders should consult their tax advisors as to their qualifications for an exemption for backup withholding and the procedure for obtaining such an exemption. In addition, payments to anon-U.S. holder and proceeds from certain dispositions of a note may be reported to the IRS and may also be made available to the tax authorities in the country in which thenon-U.S. holder resides under the provisions of an applicable income tax treaty. Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules from a payment to anon-U.S. holder may be credited against thenon-U.S. holder’s U.S. federal income tax liability, if any, or refunded, if the required information is furnished to the IRS in a timely manner.Non-U.S. holders should consult their tax advisors regarding the information reporting and backup withholding rules applicable to them.

Foreign Account Tax Compliance Act (“FATCA”). Under Sections 1471 through 1474 of the Code and the Treasury regulations and administrative guidance thereunder, commonly referred to as FATCA, U.S. federal withholding tax at a rate of 30% is imposed on U.S.-source interest on, and, on sales or redemption proceeds of, a note paid to (i) a “foreign financial institution” (as defined for this purpose) unless such institution is exempt from FATCA withholding pursuant to an applicable intergovernmental agreement between the jurisdiction in which it is located and the United States, enters into an agreement with the U.S. government to collect and

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provide to the U.S. tax authorities information regarding U.S. account holders of such institution (which would include certain equity and debt holders of such institution, as well as certain account holders that are foreign entities with U.S. owners) or meets other exemptions or (ii) a foreign entity that is not a financial institution, unless such entity is exempt from FATCA withholding pursuant to an applicable intergovernmental agreement between the jurisdiction in which it is located and the United States, provides the withholding agent with a certification identifying any substantial U.S. owners of the entity (as defined for this purpose) or meets other exemptions. However, proposed regulations may eliminate the requirement to withhold on payments of gross proceeds from dispositions.

If FATCA withholding is imposed, anon-U.S. holder that is not a foreign financial institution may under certain circumstances be eligible for a refund or credit of any amounts withheld by filing certain information with the IRS. Prospective investors should consult their own tax advisors regarding the effects of FATCA on their investment in the notes.

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CERTAIN ERISA CONSIDERATIONS

Each fiduciary of an employee benefit plan that is subject to Title I of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), plans, individual retirement accounts and other arrangements that are subject to Section 4975 of the Code, and entities whose underlying assets are considered to include “plan assets” of such plans, accounts and arrangements (each of the foregoing, a “Plan”) and plans or arrangements subject to provisions under any federal, state, local or other laws or regulations that are similar to such provisions of ERISA or the Code (“Similar Laws”) should consider the fiduciary standards of ERISA or Similar Laws (as applicable) in the context of the plan’s particular circumstances before authorizing an investment in the notes.

General Fiduciary Duties

ERISA and the Code impose certain duties on persons who are fiduciaries of a Plan and prohibit certain transactions involving the assets of a Plan and its fiduciaries or other interested parties. Under ERISA and the Code, any person who exercises any discretionary authority or control over the management or administration of such a Plan or any authority or control over the management or disposition of the assets of such a Plan, or who renders investment advice for a fee or other compensation to such a Plan, is considered to be a fiduciary of such Plan.

In considering an investment in the notes of a portion of the assets of any Plan, or any plan or arrangement subject to Similar Laws, a fiduciary should determine whether the investment is in accordance with the documents and instruments governing the Plan and the applicable provisions of ERISA, the Code or any Similar Laws relating to a fiduciary’s duties including, without limitation, the prudence, diversification, delegation of control and prohibited transaction provisions of ERISA, the Code and Similar Laws.

Prohibited Transaction Issues

Section 406 of ERISA and Section 4975 of the Code prohibit Plans from engaging in specified transactions involving plan assets with persons or entities who are “parties in interest,” within the meaning of ERISA, or “disqualified persons,” within the meaning of Section 4975 of the Code, unless an exemption is available. A party in interest or disqualified person who engages in anon-exempt prohibited transaction may be subject to excise taxes and other penalties and liabilities under ERISA and the Code. In addition, the fiduciary of the Plan that engages in such anon-exempt prohibited transaction may be subject to penalties and liabilities under ERISA and the Code. The acquisition or holding of notes by a Plan with respect to which we or an underwriter are considered a party in interest or a disqualified person may constitute or result in a direct or indirect prohibited transaction under Section 406 of ERISA or Section 4975 of the Code, unless the investment is acquired and is held in accordance with an applicable statutory, class or individual prohibited transaction exemption. In this regard, the U.S. Department of Labor has issued prohibited transaction class exemptions (“PTCEs”) that may apply to the acquisition and holding of the notes. These class exemptions include PTCE84-14 respecting transactions determined by independent qualified professional asset managers, PTCE90-1 respecting insurance company pooled separate accounts, PTCE91-38 respecting bank collective investment funds, PTCE95-60 respecting life insurance company general accounts and PTCE96-23 respecting transactions determined byin-house asset managers. In addition, Section 408(b)(17) of ERISA and Section 4975(d)(20) of the Code provide relief from the prohibited transaction provisions of ERISA and Section 4975 of the Code for certain transactions between a Plan and a person that is a party in interest or disqualified person with respect to the Plan solely by reason of providing services to the Plan or a relationship with such a service provider, provided that neither the person transacting with the Plan nor any of its affiliates has or exercises any discretionary authority or control or renders any investment advice with respect to the assets of the Plan involved in the transaction and provided further that the Plan pays no more and receives no less than adequate consideration in connection with the transaction. There can be no assurance that any of the foregoing exemptions or any other exemption will be available with respect to the acquisition and holding of the notes or that all of the conditions of any such exemptions will be satisfied.

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Because of the foregoing, the notes should not be purchased or held by any person investing “plan assets” of any Plan, unless such purchase and holding will not constitute or result in anon-exempt prohibited transaction under ERISA and the Code, or with respect to assets of a plan or arrangement that is subject to Similar Laws, a violation of any applicable Similar Laws.

Representation

By acceptance of a note, each purchaser and subsequent transferee of a note will be deemed to have represented and warranted that either (i) no portion of the assets used by such purchaser or transferee to acquire and hold the note constitutes assets of any Plan or assets of a plan or arrangement that is subject to Similar Laws, or (ii) the purchase and holding of the note by such purchaser or transferee will not constitute or result in a nonexempt prohibited transaction under Section 406 of ERISA or Section 4975 of the Code because such purchase and holding satisfies the conditions for relief under an applicable statutory, class or individual prohibited transaction exemption (or to the extent assets of a plan or arrangement that is subject to Similar Laws are being used by such purchaser or transferee to acquire and hold the note, such purchase and holding will not constitute or result in a violation of any applicable Similar Laws).

The foregoing discussion is general in nature and is not intended to beall-inclusive. Due to the complexity of these rules and the penalties that may be imposed upon persons involved innon-exempt prohibited transactions, it is particularly important that fiduciaries, or other persons considering purchasing the notes on behalf of, or with the assets of, any Plan or assets of a plan or arrangement subject to Similar Laws, consult with their counsel regarding the potential applicability of ERISA, Section 4975 of the Code and any Similar Laws to such investment and whether an exemption would be applicable to the purchase and holding of the notes.

The sale of notes to a Plan, or to a plan or arrangement that is subject to Similar Laws, is in no respect a representation by us, the underwriters or any other person that such an investment meets all relevant legal requirements with respect to investments by such plans and arrangements generally or any particular plan or arrangement or that such an investment is appropriate for such plans and arrangements generally or any particular plan or arrangement.

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UNDERWRITING

Morgan Stanley & Co. LLC, BofA Securities, Inc., Goldman Sachs & Co. LLC and Wells Fargo Securities, LLC are acting as representatives of the underwriters named below. Under the terms and subject to the conditions contained in an underwriting agreement, dated the date of this prospectus supplement, each of the underwriters has severally agreed to purchase from us, and we have agreed to sell to that underwriter, the principal amount of notes listed next to its name in the following table.

The underwriting agreement provides that the obligations of the underwriters to pay for and accept delivery of the notes offered by this prospectus supplement and the accompanying prospectus are subject to the approval of certain legal matters by their counsel and to certain other conditions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part. The underwriters are obligated to take and pay for all of the notes offered by this prospectus supplement and the accompanying prospectus if any notes are taken. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of thenon-defaulting underwriters may be increased or the underwriting agreement may be terminated.

Notes sold by the underwriters to the public will initially be offered at the initial public offering price set forth on the cover of this prospectus supplement. Any notes sold by the underwriters to securities dealers may be sold at a discount from the initial public offering price of up to            % of the principal amount of notes. Any such securities dealers may resell any notes purchased from the underwriters to certain other brokers or dealers at a discount from the initial public offering price of up to            % of the principal amount of notes. If all the notes are not sold at the initial public offering price, the underwriters may change the initial public offering price and the other selling terms.

We have agreed that, for the period ending at the time the notes are issued and delivered, we will not, without the prior written consent of the representatives, (i) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of, directly or indirectly, any notes, or any other indebtedness of the Corporation substantially similar to the notes, or any securities convertible into or exercisable or exchangeable for notes, or any other indebtedness of the Corporation substantially similar to the notes, or (ii) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the notes, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of the notes or such other securities, in cash or otherwise, other than the notes offered hereby.

Our expenses with respect to this offering, not including the underwriting discount, are estimated to be approximately $            and will be payable by us. The underwriters have agreed to reimburse us for $            of such expenses.

The notes are a new issue of securities and have no established trading market and will not be listed on any securities exchange or automated quotation system. We have been advised by the underwriters that they presently intend to make a market in the notes, as permitted by applicable laws and regulations.

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The underwriters are not obligated, however, to make a market in the notes and may discontinue any market making at any time without notice at their sole discretion. Even if a secondary market for the notes develops, it may not provide significant liquidity and transaction costs in any secondary market could be high. As a result, the difference between bid and asked prices in any secondary market could be substantial. Accordingly, we cannot make any assurance as to the liquidity of, or trading markets for, the notes.

To facilitate the offering of the notes, the underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the notes. Specifically, the underwriters may sell more notes than they are obligated to purchase under the underwriting agreement, creating a naked short position. The underwriters must close out any naked short position by purchasing notes in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of the notes in the open market after pricing that could adversely affect investors who purchase in the offering. As an additional means of facilitating the offering, the underwriters may bid for, and purchase, notes in the open market to stabilize the price of the notes. These activities may raise or maintain the market price of the notes above independent market levels or prevent or retard a decline in the market price of the notes. The underwriters are not required to engage in these activities, and may end any of these activities at any time without notice.

The underwriters may also impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representatives have repurchased notes sold by or for the account of such underwriter in stabilizing or short covering transactions.

In general, purchases of a security for the purpose of stabilizing or reducing a syndicate short position could cause the price of the security to be higher than it might otherwise be in the absence of such purchases. If these activities are commenced, they may be discontinued by the underwriters at any time without notice.

Neither we nor the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of the notes. In addition, neither we nor the underwriters make any representation that the underwriters will engage in such transactions or that such transactions will not be discontinued without notice, once they are commenced.

We have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act of 1933, as amended. If we are unable to provide this indemnification, we will contribute to payments the underwriters may be required to make in respect of those liabilities.

The underwriters and their respective affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. Certain of the underwriters and certain of their respective affiliates have performed banking, investment banking, custodial and advisory services for us and our affiliates, from time to time, for which they have received customary fees and expenses. The underwriters and their respective affiliates may, from time to time, engage in transactions with and perform services for us in the ordinary course of their business for which they will receive customary fees and expenses.

In the ordinary course of their various business activities, the underwriters and their respective affiliates have made or held, and may in the future make or hold, a broad array of investments including serving as counterparties to certain derivative and hedging arrangements, and may have actively traded, and, in the future may actively trade, debt and equity securities (or related derivative securities), and financial instruments (including bank loans) for their own account and for the accounts of their customers and may have in the past and

at any time in the future hold long and short positions in such securities and instruments. Such investment and securities activities may have involved and in the future may involve our securities and instruments. Certain of the underwriters or their affiliates that have a lending relationship with us routinely hedge their credit exposure to us consistent with their customary risk management policies. Typically, such underwriters and their affiliates

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would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. The underwriters and their respective affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Delivery is expected to be made against payment for the notes on            , 2020, which will be the third business day following the date hereof (this settlement cycle being referred to as “T+3”). Under Rule15c6-1 of the Securities Exchange Act of 1934, as amended, trades in the secondary market generally are required to settle in two business days, unless the parties to that trade expressly agree otherwise. Accordingly, purchasers who wish to trade notes on the date hereof will be required, by virtue of the fact that the notes initially will settle in T+3, to specify an alternate settlement cycle at the time of any such trade to prevent a failed settlement and should consult their own advisors.

Selling Restrictions

European Economic Area and United Kingdom

The notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the European Economic Area (“EEA”) or the United Kingdom (the “UK”). For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU (as amended, “MiFID II”); or (ii) a customer within the meaning of Directive (EU) 2016/97 (the “Insurance Distribution Directive”), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or (iii) not a qualified investor as defined in Regulation (EU) 2017/1129 (the “Prospectus Regulation”). Consequently no key information document required by Regulation (EU) No 1286/2014 (as amended, the “PRIIPs Regulation”) for offering or selling the notes or otherwise making them available to retail investors in the EEA or in the UK has been prepared and therefore offering or selling the notes or otherwise making them available to any retail investor in the EEA or in the UK may be unlawful under the PRIIPs Regulation. This prospectus supplement and the accompanying prospectus have been prepared on the basis that any offer of notes in any Member State of the EEA or in the UK will be made pursuant to an exemption under the Prospectus Regulation from the requirement to publish a prospectus for offers of notes. This prospectus supplement and the accompanying prospectus are not a prospectus for the purposes of the Prospectus Regulation.

United Kingdom

Each underwriter has represented and agreed that:

This prospectus supplement is only being distributed to, and is only directed at, (i) persons who are outside the United Kingdom or (ii) investment professionals falling within Article 19(5) of the FSMA (Financial Promotion) Order 2005 (the “Order”), or (iii) high net worth entities, and other persons to whom it may lawfully be communicated, falling within Article 49(2)(a) to (d) of the Order, all such persons together being referred to as “relevant persons.” The notes are only available to, and investment activity will only be engaged in with, relevant persons. Any person that is not a relevant person should not act or rely on this document or any of its contents.

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Hong Kong

The notes may not be offered or sold by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap.32, Laws of Hong Kong), or (ii) to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap.571, Laws of Hong Kong) and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” within the meaning of the Companies Ordinance (Cap.32, Laws of Hong Kong), and no advertisement, invitation or document relating to the notes may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the laws of Hong Kong) other than with respect to notes which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder.

Japan

The notes have not been and will not be registered under the Financial Instruments and Exchange Law of Japan (the “Financial Instruments and Exchange Law”) and each underwriter has agreed that it will not offer or sell any notes, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others for reoffering or resale, directly or indirectly, in Japan or to a resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the Financial Instruments and Exchange Law and any other applicable laws, regulations and ministerial guidelines of Japan.

Singapore

This prospectus supplement and the accompanying prospectus have not been and will not be registered as a prospectus with the Monetary Authority of Singapore under the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”). Accordingly, each underwriter has not offered or sold any notes or caused such notes to be made the subject of an invitation for subscription or purchase and will not offer or sell such notes or cause such notes to be made the subject of an invitation for subscription or purchase, and has not circulated or distributed, nor will it circulate or distribute, this prospectus supplement, the accompanying prospectus or any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of such notes, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the SFA, (ii) to a relevant person pursuant to Section 275(1), or any person pursuant to Section 275(1A), and in accordance with the conditions, specified in Section 275, of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the notes are subscribed or purchased under Section 275 of the SFA by a relevant person which is: (a) a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or (b) a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary of the trust is an individual who is an accredited investor, securities (as defined in Section 239(1) of the SFA) of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the notes pursuant to an offer made under Section 275 of the SFA except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person (as defined in Section 275(2) of the SFA), or to any person arising from an offer referred to in Section 275(1A), or Section 276(4)(i)(B) of the SFA; (2) where no consideration is or will be given for the transfer; (3) where the transfer is by operation of law; (4) as specified in Section 276(7) of the SFA; or (5) as specified in Regulation 32 of the Securities and Futures (Offers of Investments) (Shares and Debentures) Regulations 2005 of Singapore.

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Singapore Securities and Futures Act Product Classification—Solely for the purposes of its obligations pursuant to sections 309B(1)(a) and 309B(1)(c) of the SFA, the Corporation has determined, and hereby notifies all relevant persons (as defined in Section 309A of the SFA) that the notes are “prescribed capital markets products” (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and Excluded Investment Products (as defined in MAS Notice SFA04-N12: Notice on the Sale of Investment Products and MAS NoticeFAA-N16: Notice on Recommendations on Investment Products).

Canada

The notes may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in NationalInstrument 45-106Prospectus Exemptions or subsection 73.3(1) of theSecurities Act (Ontario), and are permitted clients, as defined in NationalInstrument 31-103Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the notes must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement and the accompanying prospectus (including any amendment hereto and thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of NationalInstrument 33-105Underwriting Conflicts(“NI 33-105”), the underwriters are not required to comply with the disclosure requirements ofNI 33-105 regarding underwriter conflicts of interest in connection with this offering.

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LEGAL MATTERS

The validity of the notes will be passed upon for us by Mayer Brown LLP, Chicago, Illinois. The underwriters have been represented by McDermott Will & Emery LLP, Chicago, Illinois.

EXPERTS

The consolidated financial statements of Northern Trust Corporation and subsidiaries as of December 31, 2019 and 2018, and for each of the years in the three-year period ended December 31, 2019, and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2019, which are included in our Annual Report on Form10-K for the fiscal year ended December 31, 2019, have been incorporated by reference herein and in the registration statement in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

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PROSPECTUS

Northern Trust Corporation

DEBT SECURITIES

PREFERRED STOCK

DEPOSITARY SHARES

COMMON STOCK

STOCK PURCHASE CONTRACTS

STOCK PURCHASE UNITS

WARRANTS

We may offer and sell debt securities, preferred stock, depositary shares, common stock, stock purchase contracts, stock purchase units and warrants from time to time, in amounts, on terms and at prices that will be determined at the time of offering. We will provide specific terms of any securities offered, including their offering prices, in one or more prospectus supplements to this prospectus. The prospectus supplements may also add, update or change information contained in this prospectus. You should read this prospectus and any prospectus supplement carefully before you invest.

We may offer these securities to or through underwriters, through dealers or agents, directly to you or through a combination of these methods. You can find additional information about our plan of distribution for the securities under the heading “Plan of Distribution” beginning on page 29 of this prospectus. We will also describe the plan of distribution for any particular offering of these securities in the applicable prospectus supplement. This prospectus may not be used to sell our securities unless it is accompanied by a prospectus supplement.

Our common stock is listed on the NASDAQ Global Select Market under the symbol “NTRS.”

Investing in our securities involves risk. See “Risk Factors” beginning on page 3 of this prospectus. You should carefully review the risks and uncertainties described under the heading “Risk Factors” contained in the applicable prospectus supplement and under similar headings in the other documents that are incorporated herein by reference.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus or any applicable prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The securities will be equity securities or debt securities of Northern Trust Corporation and will not be savings accounts, deposits or other obligations of any bank or nonbank subsidiary of Northern Trust Corporation and are not insured by the Federal Deposit Insurance Corporation any other government agency.

The date of this prospectus is July 31, 2017.

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

This prospectus is part of an “automatic shelf” registration statement that we filed with the U.S. Securities and Exchange Commission, or SEC, as a “well-known seasoned issuer” as defined in Rule 405 under the Securities Act of 1933, as amended, or the Securities Act. Under this shelf registration process, we may sell, from time to time, an indeterminate amount of any combination of the securities described in this prospectus in one or more offerings.

This prospectus provides you with a general description of the securities we may offer, which is not meant to be a complete description of each security. Each time we offer securities registered under this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering, including the specific amounts, prices and terms of the securities offered. That prospectus supplement may include a description of any risk factors or other special considerations applicable to those securities. The prospectus supplement may also add, update or change information contained in this prospectus or in documents we have incorporated by reference into this prospectus. If there is any inconsistency between the information in the prospectus and the prospectus supplement, you should rely on the information in the prospectus supplement. You should read both this prospectus and the applicable prospectus supplement and any other offering material (including any free writing prospectus) prepared by or on behalf of us for a specific offering of securities together with the additional information described under the heading “Where You Can Find More Information” in this prospectus before you invest.

You should rely only on the information incorporated by reference or provided in this prospectus and any prospectus supplement. We have not authorized anyone to provide you with different information. We are not making an offer to sell or soliciting an offer to buy these securities in any jurisdiction in which the offer or solicitation is not authorized or in which the person making the offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make the offer or solicitation. You should not assume that the information in this prospectus, any prospectus supplement or any related free writing prospectus or any document incorporated by reference is accurate as of any date other than the date on the front of the applicable document. Neither the delivery of this prospectus or any applicable prospectus supplement or other offering material (including any free writing prospectus) nor any distribution of securities pursuant to such documents shall, under any circumstances, create any implication that there has been no change in the information set forth in this prospectus or any applicable prospectus supplement or other offering material or in our and our subsidiaries’ affairs since the date of this prospectus or any applicable prospectus supplement or other offering material.

Any of the securities described in this prospectus may be convertible into or exchangeable or exercisable for other securities we describe in this prospectus or will describe in a prospectus supplement and may be issued separately, together or as part of a unit consisting of two or more securities, which may or may not be separate from one another. These securities may include new or hybrid securities developed in the future that combine features of any of the securities described in this prospectus.

Unless otherwise indicated or the context otherwise requires, references in this prospectus to “Northern Trust,” “we,” “us” and “our” are to Northern Trust Corporation and its consolidated subsidiaries. References to “the Corporation” are to Northern Trust Corporation. References to “the Bank” are to The Northern Trust Company. References to “securities” include any security that we might sell under this prospectus or any prospectus supplement. References to “$” and “dollars” are to the currency of the United States.

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WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3 under the Securities Act, relating to the securities described in this prospectus. As permitted by the rules and regulations of the SEC, we have not included certain portions of the registration statement in this prospectus. Accordingly, this prospectus does not contain all of the information set forth in the registration statement and the exhibits filed or incorporated by reference as part of the registration statement. The registration statement, including the attached exhibits and schedules, contains additional relevant information about us.

The Corporation files annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy any document the Corporation files at the SEC’s public reference room at 100 F Street, N.E., Washington, D.C. 20549. You may obtain additional information about the public reference room by calling the SEC at 1-800-SEC-0330. In addition, the SEC maintains a site on the Internet (www.sec.gov) that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC, including the Corporation.

The SEC allows us to “incorporate by reference” information into this prospectus. This means that we can disclose important information to you by referring you to another document that the Corporation has filed, or will file, separately with the SEC. The information incorporated by reference is considered to be part of this prospectus. Information that the Corporation files with the SEC after the date of this prospectus will automatically modify and supersede the information included or incorporated by reference in this prospectus to the extent that the subsequently filed information modifies or supersedes the existing information. The following documents filed with the SEC are hereby incorporated by reference:

We also incorporate by reference any future filings we make with the SEC under sections 13(a), 13(c), 14 or 15(d) of the Exchange Act until the termination of this offering. Nothing in this prospectus shall be deemed to incorporate by reference information furnished to, but not filed with, the SEC.

You may request a copy of any of these filings at no cost by writing to or telephoning us at the following address and telephone number: Northern Trust Corporation, 50 South LaSalle Street, Chicago, Illinois 60603, Telephone: (312) 444-2301, Attention: Investor Relations.

We maintain an Internet site atwww.northerntrust.com which contains information concerning Northern Trust. The information contained at our Internet site is not incorporated by reference in this prospectus or any prospectus supplement or other offering materials, and you should not consider it a part of this prospectus or any prospectus supplement or other offering materials.

Any statement made in this prospectus concerning the contents of any contract, agreement or other document is only a summary of the actual document. If we have filed any contract, agreement or other document as an exhibit to the registration statement, you should read the exhibit for a more complete understanding of the document or matter involved. Each statement regarding a contract, agreement or other document is qualified in its entirety by reference to the actual document.

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RISK FACTORS

Investing in the securities involves certain risks. Before making an investment decision, you should carefully read and consider the “Risk Factors” section in our most recent Annual Report on Form 10-K, which is incorporated by reference in this prospectus, as updated by our future filings with the SEC, in addition to all other information contained or incorporated by reference into this prospectus, any prospectus supplement or other offering materials. These risks, as well as those not presently known to us or that we currently deem immaterial, could materially and adversely affect our operating results and financial condition and the value of your investment. The prospectus supplement applicable to each type or series of securities we offer may contain a discussion of additional risks applicable to an investment in us and the particular type of securities we are offering under that prospectus supplement. For more information, see the section entitled “Where You Can Find More Information” in this prospectus. You also should review carefully the cautionary statement section of this prospectus entitled “Forward-Looking Statements.”

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FORWARD-LOOKING STATEMENTS

This prospectus and any applicable prospectus supplement, including the documents incorporated by reference herein and therein, and other statements that we may make, may contain forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, with respect to our financial results and outlook, capital adequacy, dividend policy, accounting estimates and assumptions, credit quality including allowance levels, future pension plan contributions, anticipated tax benefits, anticipated expense levels, spending related to technology and regulatory initiatives, risk management policies, contingent liabilities, strategic initiatives, industry trends, and expectations regarding the impact of recent legislation and accounting pronouncements, and all other statements that do not relate to historical facts.

Forward-looking statements are typically identified by words or phrases such as “believe,” “expect,” “anticipate,” “intend,” “estimate,” “project,” “likely,” “plan,” “goal,” “target,” “strategy,” and similar expressions or future or conditional verbs such as “may,” “will,” “should,” “would,” and “could.” You should read carefully the risk factors described in “Risk Factors” herein and in the documents incorporated by reference in this prospectus and the applicable prospectus supplement for a description of certain risks that could, among other things, cause our actual results to differ from these forward-looking statements.

Forward-looking statements are based on our current beliefs and expectations of future events or future results and involve risks and uncertainties that are difficult to predict and subject to change. These statements are also based on assumptions about many important factors, including:

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Actual results may differ materially from those expressed or implied by forward-looking statements. The information contained in this prospectus, any applicable prospectus supplement and any other offering materials, as well as information incorporated by reference herein or therein, is accurate only as of the date of that information. All forward-looking statements included in such documents are based upon information available at the time such statements are made, and we assume no obligation to update any forward-looking statements.

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NORTHERN TRUST CORPORATION

We are a financial holding company that is a leading provider of asset servicing, fund administration, asset management, fiduciary and banking solutions for corporations, institutions, families and individuals worldwide. We conduct our business through various U.S. and non-U.S. subsidiaries, including the Bank. We were originally formed as a holding company for the Bank in 1971. We have a network of offices in 19 U.S. states, Washington, D.C., and 22 international locations in Canada, Europe, the Middle East and the Asia-Pacific region. At June 30, 2017, we had consolidated total assets of $125.6 billion and stockholders’ equity of $10.1 billion.

The Bank is an Illinois banking corporation headquartered in Chicago and our principal subsidiary. Founded in 1889, the Bank conducts its business through its U.S. operations and its various U.S. and non-U.S. branches and subsidiaries. At June 30, 2017, the Bank had consolidated assets of $125.2 billion and common bank equity capital of $9.0 billion.

We expect that the Bank will continue in the foreseeable future to be the major source of our consolidated assets, revenues and net income.

Business Overview

We focus on managing and servicing client assets through our two client-focused reporting segments: Corporate & Institutional Services, or C&IS, and Wealth Management. Asset management and related services are provided to C&IS and Wealth Management clients primarily by the Asset Management business. The revenue and expenses of Asset Management and certain other support functions are allocated fully to C&IS and Wealth Management. We also make use of a third reporting segment, Treasury and Other, under which we report certain income and expense items not allocated to C&IS and Wealth Management.

Corporate and Institutional Services

C&IS is a leading global provider of asset servicing and related services to corporate and public retirement funds, foundations, endowments, fund managers, insurance companies, sovereign wealth funds and other institutional investors around the globe. Asset servicing and related services encompass a full range of capabilities including, but not limited to: global custody; fund administration; investment operations outsourcing; investment management; investment risk and analytical services; employee benefit services; securities lending; foreign exchange; treasury management; brokerage services; transition management services; banking; and cash management. Client relationships are managed through the Bank and the Bank’s and our other subsidiaries, including support from locations in North America, Europe, the Middle East and the Asia-Pacific region. At June 30, 2017, total C&IS assets under custody were $6.8 trillion and assets under management were $762.7 billion.

Wealth Management

Wealth Management focuses on high-net-worth individuals and families, business owners, executives, professionals, retirees and established privately-held businesses in its target markets. The business also includes the Global Family Office, which provides customized services to meet the complex financial needs of individuals and family offices in the United States and throughout the world with assets typically exceeding $200 million. In supporting these targeted segments, Wealth Management provides trust, investment management, custody and philanthropic services; financial consulting; guardianship and estate administration; family business consulting; family financial education; brokerage services; and private and business banking.

Wealth Management is one of the largest providers of advisory services in the United States, with $593.3 billion in assets under custody and $266.1 billion in assets under management at June 30, 2017. Wealth Management services are delivered by multidisciplinary teams through a network of offices in 18 U.S. states and Washington, D.C., as well as offices in London, Guernsey and Abu Dhabi.

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Asset Management

Asset Management, through our various subsidiaries, supports the C&IS and Wealth Management reporting segments by providing a broad range of asset management and related services and other products to clients around the world. Investment solutions are delivered through separately managed accounts, bank common and collective funds, registered investment companies, exchange traded funds, non-U.S. collective investment funds and unregistered private investment funds. Asset Management’s capabilities include active, passive and engineered equity; active and passive fixed income; cash management; alternative asset classes (such as private equity and hedge funds of funds); and multi-manager advisory services and products. Asset Management’s activities also include overlay services and other risk management services. Asset Management operates internationally through subsidiaries and distribution arrangements and its revenue and expense are fully allocated to C&IS and Wealth Management. As discussed above, Northern Trust managed $1.0 trillion in assets as of June 30, 2017, including $762.7 billion for C&IS clients and $266.1 billion for Wealth Management clients.

Corporate Information

Our principal executive offices are located at 50 South LaSalle Street, Chicago, Illinois 60603, and our telephone number is (312) 630-6000.

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RATIOS OF EARNINGS TO FIXED CHARGES AND COMBINED FIXED CHARGES AND PREFERRED STOCK DIVIDENDS

The following are ratios of our earnings to fixed charges and earnings to combined fixed charges and preferred stock dividends for each of the periods indicated:

For purposes of calculating the ratios of earnings to fixed charges and earnings to combined fixed charges and preferred stock dividends, “earnings” consist of net income before extraordinary items plus applicable income taxes and fixed charges. “Fixed charges, excluding interest on deposits” consist of interest expense (other than on deposits) and the estimated interest component of rental expense. “Fixed charges, including interest on deposits” consist of all interest expense and the estimated interest component of rental expense.

USE OF PROCEEDS

We expect to use the net proceeds from the sale of securities offered by this prospectus and any applicable prospectus supplement for general corporate purposes unless otherwise indicated in the applicable prospectus supplement. General corporate purposes may include, without limitation, working capital, capital expenditures, investments in, or extensions of credit to, our subsidiaries, refinancing of debt, share repurchases, dividends, funding potential future acquisitions and satisfaction of other obligations. We may temporarily invest the net proceeds or use them to repay short-term debt until they are used for their stated purpose.

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DESCRIPTION OF THE DEBT SECURITIES

We may offer debt securities, which may be senior debt securities or subordinated debt securities and may be convertible or nonconvertible, as well as secured or unsecured. The following description briefly sets forth certain general terms and provisions of the debt securities. The particular terms of the debt securities offered by any prospectus supplement and the extent, if any, to which these general provisions may apply to the debt securities, will be described in the applicable prospectus supplement.

Unless otherwise specified in the applicable prospectus supplement, our debt securities will be issued in one or more series under the indenture dated May 8, 2017, as amended or supplemented from time to time, between us and The Bank of New York Mellon Trust Company, N.A., acting as a trustee, a copy of which is incorporated by reference as an exhibit to the registration statement of which this prospectus forms a part. The terms of the debt securities will include those set forth in the indenture and those made a part of the indenture by the Trust Indenture Act of 1939, or the TIA. You should read the summary below, the applicable prospectus supplement and the provisions of the indenture and indenture supplement, if any, in their entirety before investing in our debt securities.

General

The aggregate principal amount of debt securities that may be issued under the indenture is unlimited. The prospectus supplement relating to any series of debt securities that we may offer will contain the specific terms of the debt securities. These terms may include the following:

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We may sell the debt securities, including original issue discount securities, at par or at a substantial discount below their stated principal amount. Unless we inform you otherwise in a prospectus supplement, we may issue additional debt securities of a particular series without the consent of the holders of the debt securities of such series or any other series outstanding at the time of issuance. Any such additional debt securities, together with all other outstanding debt securities of that series, may constitute a single series of securities under the indenture.

We will describe in the applicable prospectus supplement any other special considerations for any debt securities we sell which are denominated in a currency or currency unit other than U.S. dollars. In addition, debt securities may be issued where the amount of principal and/or interest payable is determined by reference to one or more currency exchange rates, commodity prices, equity indices or other factors. Holders of such securities may receive a principal amount or a payment of interest that is greater than or less than the amount of principal or interest otherwise payable on such dates, depending upon the value of the applicable currencies, commodities, equity indices or other factors. We will describe in the applicable prospectus supplement information as to the methods for determining the amount of principal or interest, if any, payable on any date, the currencies, commodities, equity indices or other factors to which the amount payable on such date is linked.

U.S. federal income tax consequences and special considerations, if any, applicable to any such series will be described in the applicable prospectus supplement. Unless we inform you otherwise in the applicable prospectus supplement, the debt securities will not be listed on any securities exchange.

Registration and Transfer

Unless otherwise indicated in the applicable prospectus supplement, we will issue each series of debt securities in fully registered form without coupons and in denominations of $2,000 and any integral multiples of

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$1,000 in excess thereof. Subject to the limitations provided in the indenture and in the applicable prospectus supplement, debt securities that are issued in registered form may be transferred or exchanged at the office or agency maintained by us for such purpose, without the payment of any service charge, other than any tax or other governmental charge payable in connection therewith.

Payment and Place of Payment

Unless otherwise indicated in the applicable prospectus supplement, we will pay principal of and any premium and interest on the debt securities to holders of record at the office or agency maintained by us for such purpose.

Events of Default

Unless otherwise indicated in the applicable prospectus supplement, an event of default under the indenture with respect to any series of debt securities will mean any of the following:

If an event of default under the indenture occurs and is continuing for any series of debt securities, other than an event of default resulting from a bankruptcy, insolvency or reorganization of the Corporation, the trustee or the holders of at least 25% in principal amount of the outstanding securities of that series may declare the principal amount of all the securities of that series, or such amount provided for in the debt securities of that series, and all accrued but unpaid interest on all the securities of that series to be due and payable immediately. The debt securities will automatically be accelerated upon the occurrence of an event of default resulting from a bankruptcy, insolvency or reorganization of the Corporation.

In the case of a default in the payment of interest or principal, or premium, if any, we will be required, upon the demand of the trustee, to pay, for the benefit of the holders of the debt securities, the whole amount then due and payable on such debt securities with interest on any overdue principal, and premium, if any, and, to the extent that payment of such interest shall be legally enforceable, on any overdue interest, at the rate or rates prescribed in such debt securities.

If we fail to pay such amounts upon demand, the trustee may institute any action or proceeding at law or in equity for the collection of the sums so due and unpaid, and may prosecute any such action or proceeding to judgment or final decree, and may enforce any such judgment or final decree against the Corporation or any other obligor upon the debt securities of such series, and collect the moneys adjudged or decreed to be payable out of the property of the Corporation or any other obligor upon the debt securities of such series, wherever situated, in the manner provided by law.

The holders of a majority in principal amount of the outstanding debt securities of a series may direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any

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trust or power conferred on the trustee with respect to debt securities of that series, provided that any such direction is not in conflict with the indenture, could lawfully be taken, would not be unduly prejudicial to holders not joining in such direction and would not involve the trustee in personal liability, and the trustee may take any other action deemed proper by the trustee that is not inconsistent with such direction. Subject to the provisions of the indenture relating to the duties of the trustee, before proceeding to exercise any right or power under the indenture at the direction of the holders, the trustee is entitled to receive from those holders security or indemnity satisfactory to it against the costs, expenses and liabilities which might be incurred by it in complying with any direction.

No holder of any debt security of any series will have the right to institute any action, suit or proceeding with respect to an event of default, unless:

However, any holder of a debt security has the absolute right to institute suit for any defaulted payment after the due dates for payment under that debt security.

We are required to furnish an officer’s certificate to the trustee each year that states, to the knowledge of the certifying officer, whether we have complied with all conditions and covenants under the terms of the indenture, and, in the event of any default under the indenture, specifying such default and the nature and status thereof to the extent of the certifying officer’s knowledge.

Modification and Waiver

Modification

We and the trustee may, with the consent of holders of at least a majority in aggregate principal amount of the debt securities of each series affected, modify and amend the indenture; however, without the consent of each holder of any debt security affected, we may not amend or modify the indenture to:

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We and the trustee may modify and amend the indenture without the consent of the holders of the debt securities for specified purposes, including, among other things, to:

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Waiver of Default

The holders of a majority in principal amount of the outstanding debt securities of any series generally may, on behalf of the holders of all the debt securities of that series, waive an event of default under the indenture with respect to that series and the consequences thereof. However, a default in the payment of the principal of, or premium, if any, or any interest on, any of the debt securities of that series cannot be so waived.

Merger, Consolidation and Sale of Assets

The Corporation may not consolidate with or merge into any other person or sell, convey, transfer or lease all or substantially all its assets to any other person, unless:

The second bullet above shall not apply to: (i) any sale, conveyance, transfer or lease between or among the Corporation and one or more of its wholly-owned subsidiaries; (ii) any merger of the Corporation into any wholly-owned subsidiary of the Corporation; or (iii) any merger of the Corporation into an affiliate of the Corporation for the purpose of reincorporating or reorganizing.

The indenture provides that the person formed by such consolidation or into which the Corporation is merged or to which such sale, conveyance, transfer or lease is made shall succeed to, and be substituted for, and may exercise every right and power of, the Corporation under the indenture with the same effect as if such successor person had been named as the Corporation in the indenture. In the event of a succession in compliance with this covenant, except in the case of a lease, the predecessor shall be relieved of and discharged from all of its obligations and covenants under the indenture and the debt securities.

Discharge and Covenant Defeasance

Unless otherwise specified in the applicable prospectus supplement, we may discharge all of our obligations with respect to the debt securities of any series at any time, and we may also be released from our obligations under certain covenants that are described in the indenture with respect to such debt securities, if any, and elect not to comply with those sections and obligations without creating an event of default. Discharge under the first procedure is called “discharge” and under the second procedure is called “covenant defeasance.”

Discharge or covenant defeasance may be effected only if:

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Satisfaction and Discharge

Unless otherwise specified in the applicable prospectus supplement, we may terminate our obligations with respect to the debt securities of any series not previously delivered to the trustee for cancellation when all such securities:

by depositing with the trustee or paying agent, as trust funds in trust for that purpose, an amount sufficient to pay and discharge the entire indebtedness on such debt securities.

Subordination

The terms of any series of debt securities under the indenture may provide that such series will be subordinated in right of payment to all senior indebtedness (as defined below). In certain circumstances relating to our dissolution, winding up, liquidation, or reorganization, whether in bankruptcy, insolvency or similar proceedings, the holders of all senior indebtedness will first be entitled to receive payment in full before the holders of subordinated debt securities will be entitled to receive any payment on such subordinated debt securities.

In addition, in the event of any default on senior indebtedness that permits the holders thereof to accelerate the maturity of the senior indebtedness, no payment may be made on subordinated debt securities if notice of such default has been given to us or if judicial proceedings are pending in respect of such default.

Unless otherwise specified in the prospectus supplement relating to the particular series of subordinated debt securities, senior indebtedness is defined in the indenture as the principal of, premium, if any, and unpaid interest on:

in each case, whether outstanding on the date of the indenture or thereafter created, incurred, assumed or guaranteed, other than:

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The indenture does not limit the amount of indebtedness, including senior indebtedness, that the Corporation or any of its subsidiaries may issue.

Due to the different subordination provisions of the various series of subordinated indebtedness issued by us, in the event of a dissolution, winding-up, liquidation, reorganization or insolvency, holders of a particular series of subordinated debt securities may recover less, ratably, than holders of other series of our outstanding subordinated indebtedness. In addition, subordinated debt securities may be fully subordinated to interests held by the U.S. government in the event of a receivership, insolvency, liquidation or similar proceeding involving the Corporation, including a proceeding under the orderly liquidation authority provisions of the Dodd-Frank Wall Street Reform and Consumer Protection Act.

The applicable prospectus supplement may further describe or alter the provisions, if any, which may apply to the subordination of the subordinated debt securities of a particular series.

Global Securities

Unless we inform you otherwise in the applicable prospectus supplement, the debt securities of a series may be issued in whole or in part in the form of one or more global securities that will be deposited with, or on behalf of, a depositary identified in the applicable prospectus supplement. Global securities will be issued in registered form and in either temporary or definitive form. Unless and until it is exchanged in whole or in part for the individual debt securities, a global security may not be transferred except as a whole by the depositary for such global security to a nominee of such depositary or by a nominee of such depositary to such depositary or another nominee of such depositary or by such depositary or any such nominee to a successor of such depositary or a nominee of such successor. The specific terms of the depositary arrangement with respect to any debt securities of a series and the rights of and limitations upon owners of beneficial interests in a global security will be described in the applicable prospectus supplement.

Governing Law

The indenture and the debt securities shall be governed by and construed in accordance with the laws of the State of New York.

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DESCRIPTION OF THE PREFERRED STOCK

The following summary contains a description of the general terms and provisions of the preferred stock we may issue. Other terms of any series of preferred stock will be described in the prospectus supplement relating to that series of preferred stock. The terms of any series of preferred stock may differ from the terms described below. Certain provisions of the preferred stock described below and in any prospectus supplement are not complete. You should refer to our Restated Certificate of Incorporation and the certificate of designation which will be filed with the SEC in connection with the offering of a particular series of preferred stock.

General

Under our Restated Certificate of Incorporation, our board of directors has the authority, without further stockholder action, to issue up to 10,000,000 shares of preferred stock, without par value, in one or more series, with such terms and for such consideration as the board may determine. The board of directors can determine the rights, preferences and limitations of each series. Therefore, without stockholder approval, our board of directors can authorize the issuance of preferred stock with voting, conversion and other rights that could dilute the voting power and other rights of our common stockholders. Of the 10,000,000 authorized shares of preferred stock:

The preferred stock will have the terms described in this section unless otherwise provided in the prospectus supplement relating to a particular series of the preferred stock. You should read the prospectus supplement relating to the particular series of the preferred stock being offered for specific terms, including:

Unless otherwise specified in the prospectus supplement, each series of the preferred stock will rank equally as to dividends and liquidation rights in all respects with each other series of preferred stock. The rights of

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holders of shares of each series of preferred stock to receive distributions upon our liquidation, dissolution or winding up will be subordinate to those of our general creditors.

As described under “Description of the Depositary Shares,” we may, at our option, with respect to any series of the preferred stock, elect to offer fractional interests in shares of preferred stock, and provide for the issuance of depositary receipts representing depositary shares, each of which will represent a fractional interest in a share of the series of the preferred stock. The fractional interest will be specified in the prospectus supplement relating to a particular series of the preferred stock.

Rank

Our series C preferred stock and series D preferred stock have, and any other series of preferred stock upon issuance will have, preference over our common stock with respect to the payment of dividends and the distribution of assets in the event of our liquidation, dissolution or winding up. In particular, unless otherwise specified in the prospectus supplement, the preferred stock will, with respect to the priority of the payment of dividends and the distribution of assets upon voluntary or involuntary liquidation, dissolution or winding up, rank:

Unless the terms of any preferred stock specifically provide that it will rank junior or senior to our series C preferred stock or our series D preferred stock, the series C preferred stock and series D preferred stock will be parity securities with respect to such preferred stock. The consent of at least two-thirds of the outstanding shares of each of our series C preferred stock and series D preferred stock voting as separate classes is required for us to authorize any class or series of capital stock that would rank senior to such series of preferred stock with respect to the payment of dividends or the distribution of assets on our liquidation, dissolution or winding up.

Dividends

Holders of the preferred stock of each series will be entitled to receive, when, as and if declared by our board of directors, cash dividends at such rates and on such dates described in the applicable prospectus supplement. Different series of preferred stock may be entitled to dividends at different rates or based on different methods of calculation. The dividend rate may be fixed or variable or both. Dividends will be payable to the holders of record as they appear on our books on record dates fixed by our board of directors, as specified in the applicable prospectus supplement.

Dividends on any series of the preferred stock may be cumulative or noncumulative, as described in the applicable prospectus supplement. If our board of directors does not declare a dividend payable on a dividend payment date on any series of noncumulative preferred stock, then the holders of that noncumulative preferred stock will have no right to receive a dividend for that dividend payment date, and we will have no obligation to pay the dividend accrued for that period, whether or not dividends on that series are declared payable on any future dividend payment dates. Dividends on any series of cumulative preferred stock will accrue from the date we initially issue shares of such series or such other date specified in the applicable prospectus supplement.

If full dividends are not paid on the shares of a series of preferred stock, dividends declared upon shares of preferred stock and any parity securities will be declared on a proportional basis so that the amount of dividends

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declared per share will bear to each other the same ratio that accrued dividends per share on the preferred stock, and accrued dividends, including any accumulations, on any parity securities, bear to each other. No dividends may be declared or paid or funds set apart for the payment of dividends on any junior securities unless full dividends will have been paid or declared and a sum sufficient for the payment set apart for payment on the preferred stock: (i) in the case of a series of preferred stock with cumulative dividend rights, for all dividend periods; (ii) in the case of the series C preferred stock, for the then-current dividend period; and (iii) in the case of the series D preferred stock, and any other series of preferred stock without cumulative dividend rights, for the then most recently completed dividend period.

Our ability to pay dividends on our preferred stock is subject to policies established by the Board of Governors of the Federal Reserve System, or the Federal Reserve Board.

Rights Upon Liquidation

If we liquidate, dissolve or wind up our affairs, either voluntarily or involuntarily, the holders of each series of preferred stock, will be entitled to receive, before any payment or distribution of assets is made to holders of junior securities, liquidating distributions in the amount described in the prospectus supplement relating to that series of the preferred stock, plus an amount equal to declared and unpaid dividends and, if the series of the preferred stock is cumulative, for all dividend periods prior to that point in time. If the amounts payable with respect to the preferred stock of any series and any other parity securities are not paid in full, the holders of the preferred stock of that series and of the parity securities will share proportionately in the distribution of our assets in proportion to the full liquidating distribution owed to those holders. After the holders of preferred stock are paid in full, they will have no right or claim to any of our remaining assets.

Because we are a bank holding company, our rights, the rights of our creditors and of our stockholders, including the holders of any series of preferred stock offered by this prospectus, to participate in the assets of any subsidiary upon the subsidiary’s liquidation or recapitalization may be subject to the prior claims of the subsidiary’s creditors except to the extent that we may ourselves be a creditor with recognized claims against the subsidiary.

Redemption

A series of the preferred stock may be redeemable, in whole or in part, at our option with prior Federal Reserve Board approval. In addition, a series of preferred stock may be subject to mandatory redemption pursuant to a sinking fund or otherwise. The redemption provisions that may apply to a series of preferred stock, including the redemption dates and the redemption prices for that series, will be described in the applicable prospectus supplement.

In the event of partial redemptions of preferred stock, whether by mandatory or optional redemption, our board of directors will determine the method for selecting the shares to be redeemed, which may be pro rata, by lot or by any other method determined to be fair and equitable.

On or after a redemption date, unless we default in the payment of the redemption price, dividends will cease to accrue on shares of preferred stock called for redemption. In addition, all rights of holders of the shares will terminate except for the right to receive the redemption price.

Under current regulations, bank holding companies generally may not exercise any option to redeem shares of preferred stock included as Tier 1 capital without the prior approval of the Federal Reserve Board.

Voting

Unless otherwise described in the applicable prospectus supplement, holders of the preferred stock will have no voting rights except as required by law or specifically provided for by our board of directors.

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Under regulations adopted by the Federal Reserve Board, if the holders of shares of any series of preferred stock become entitled to vote for the election of directors, such series may then be deemed a “class of voting securities.” A holder of 25% or more of such series (or a holder of 5% if it otherwise exercises a “controlling influence” over us) may then be subject to regulation as a bank holding company in accordance with the Bank Holding Company Act. In addition, at such time as such series is deemed a class of voting securities, (i) any other bank holding company may be required to obtain the approval of the Federal Reserve Board to acquire or retain 5% or more of such series, and (ii) any person other than a bank holding company may be required to file with the Federal Reserve Board under the Change in Bank Control Act, to acquire or retain 10% or more of such series. While we do not believe any series of our preferred stock is considered “voting securities” currently, holders of preferred stock should consult their own counsel with regard to regulatory implications. A holder or group of holders may also be deemed to control us if they own more than one-third of our total equity, both voting and nonvoting, aggregating all shares held by the holders across all classes of stock.

Transfer Agent and Registrar

Unless otherwise indicated in the applicable prospectus supplement, Wells Fargo Bank, N.A. will be the transfer agent, dividend and redemption price disbursement agent and registrar for shares of each series of the preferred stock.

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DESCRIPTION OF THE DEPOSITARY SHARES

General

We may, at our option, elect to offer fractional interests in shares of preferred stock, which we call depositary shares, rather than full shares of preferred stock. If we do, we will issue to the public receipts, called depositary receipts, for depositary shares, each of which will represent a fraction, to be described in the applicable prospectus supplement, of a share of a particular series of preferred stock. Unless otherwise provided in the prospectus supplement, each owner of a depositary share will be entitled, in proportion to the applicable fractional interest in a share of preferred stock represented by the depositary share, to all the rights and preferences of the preferred stock represented by the depositary share. Those rights include dividend, voting, redemption, conversion and liquidation rights.

The shares of preferred stock underlying the depositary shares will be deposited with a bank or trust company selected by us to act as depositary under a deposit agreement between us, the depositary and the holders of the depositary receipts. The depositary will be the transfer agent, registrar and dividend disbursing agent for the depositary shares.

The depositary shares will be evidenced by depositary receipts issued pursuant to the deposit agreement. Holders of depositary receipts agree to be bound by the deposit agreement, which requires holders to take certain actions such as filing proof of residence and paying certain charges.

The summary of terms of the depositary shares contained in this prospectus is not complete. You should refer to the form of the deposit agreement and the certificate of designation for the applicable series of preferred stock that are, or will be, filed with the SEC.

Dividends and Other Distributions

The depositary will distribute all cash dividends or other cash distributions, if any, received in respect of the preferred stock underlying the depositary shares to the record holders of depositary shares in proportion to the numbers of depositary shares owned by those holders on the relevant record date. The relevant record date for depositary shares will be the same date as the record date for, or otherwise in accordance with the terms of, the underlying preferred stock. The depositary will not distribute amounts less than one cent. The depositary will distribute any balance with the next sum received for distribution to record holders of depositary shares.

If there is a distribution other than in cash, the depositary will distribute property received by it to the record holders of depositary shares, unless the depositary determines that it is not feasible to make the distribution. If this occurs, the depositary may, with our approval, adopt another method for the distribution, including selling the property and distributing the net proceeds from the sale to the holders.

Liquidation Preference

If a series of preferred stock underlying the depositary shares has a liquidation preference, in the event of the voluntary or involuntary liquidation, dissolution or winding up of the Corporation, holders of depositary shares will be entitled to receive the fraction of the liquidation preference accorded each share of the applicable series of preferred stock, as set forth in the applicable prospectus supplement.

Withdrawal of Stock

Unless the related depositary shares have been previously called for redemption, upon surrender of the depositary receipts at the office of the depositary, the holder of the depositary shares will be entitled to delivery, at the office of the depositary to or upon his or her order, of the number of whole shares of the preferred stock

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and any money or other property represented by the depositary shares. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the number of depositary shares representing the number of whole shares of preferred stock to be withdrawn, the depositary will deliver to the holder at the same time a new depositary receipt evidencing the excess number of depositary shares. In no event will the depositary deliver fractional shares of preferred stock upon surrender of depositary receipts.

Redemption of Depositary Shares

Whenever we redeem shares of preferred stock held by the depositary, the depositary will redeem, as of the same redemption date, the number of depositary shares representing the preferred stock redeemed, so long as we have set aside all funds necessary for the redemption, including the redemption price for such shares and all dividends declared but not paid as of the date fixed for redemption. The redemption price per depositary share will bear the same relationship to the redemption price per share of preferred stock that the depositary share bears to the underlying preferred stock. If less than all the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected pro rata, by lot or by any other equitable method.

After the date fixed for redemption, the depositary shares called for redemption will no longer be outstanding. When the depositary shares are no longer outstanding, all rights of the holders will cease, except the right to receive money or other property that the holders of the depositary shares were entitled to receive upon the redemption. Payments will be made when holders surrender their depositary receipts to the depositary.

Voting the Preferred Stock

Upon receipt of notice of any meeting at which the holders of the preferred stock are entitled to vote, the depositary will forward the information contained in the notice of meeting to the record holders of the depositary receipts relating to that preferred stock. The relevant record date for depositary shares will be the same date as the record date for, or otherwise in accordance with the terms of, the underlying preferred stock. Each record holder of the depositary shares on the record date will be entitled to instruct the depositary as to the exercise of the voting rights pertaining to the number of shares of preferred stock represented by that holder’s depositary shares. The depositary will endeavor, insofar as reasonably practicable, to vote the number of shares of preferred stock represented by the depositary shares in accordance with those instructions, and we will agree to take all reasonable action requested by and deemed necessary by the depositary in order to enable the depositary to do so. In the absence of any specific instructions from a holder of depositary shares, the depositary will, subject to any applicable restrictions, cast votes pertaining to the number of whole shares of preferred stock represented by such depositary shares proportionately with instructions actually received.

Charges of Depositary

We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will pay associated charges of the depositary in connection with the initial deposit of the preferred stock and any redemption of the preferred stock. Holders of depositary receipts will pay transfer, income and other taxes and governmental charges and such other charges as are expressly provided in the deposit agreement to be for their accounts. If these charges have not been paid by the holders of depositary receipts, the depositary may refuse to transfer depositary shares, withhold dividends and distributions and sell the depositary shares evidenced by the depositary receipt.

Amendment and Termination of the Deposit Agreement

The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may be amended by agreement between us and the depositary. However, any amendment that materially and adversely alters the rights of the holders of depositary shares will not be effective unless the amendment has been approved by at least a majority (or, in the case of such amendments relating to or affecting rights to receive

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dividends or distributions or voting or redemption rights, holders of at least two-thirds) of the outstanding depositary shares. The deposit agreement may be terminated by the depositary or us only if:

Resignation and Removal of Depositary

The depositary may resign at any time by delivering to us notice of its election to do so, and we may remove the depositary at any time. Any resignation or removal of the depositary will take effect upon our appointment of a successor depositary and its acceptance of such appointment. The successor depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having the requisite combined capital and surplus as set forth in the applicable agreement.

Notices

The depositary will forward to holders of depositary receipts all notices, reports and other communications, including proxy solicitation materials received from us, that are delivered to the depositary and that we are required to furnish to the holders of the preferred stock. In addition, the depositary will make available for inspection by holders of depositary receipts at the principal office of the depositary, and at such other places as it may from time to time deem advisable, any reports and communications we deliver to the depositary as the holder of preferred stock.

Limitation of Liability

Neither we nor the depositary will be liable if either of us is prevented or delayed by law or any circumstance beyond its control in performing its obligations under the deposit agreement. Our obligations and those of the depositary under the deposit agreement will be limited to performance in good faith of our and their obligations thereunder. We and the depositary will not be obligated to prosecute or defend any legal proceeding in respect of any depositary shares or preferred stock unless satisfactory indemnity is furnished. We and the depositary may rely upon advice of counsel or accountants, on information provided by persons presenting preferred stock for deposit, holders of depositary receipts or other persons believed to be competent to give such information and on documents believed to be genuine and to have been signed or presented by the proper party or parties.

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DESCRIPTION OF THE COMMON STOCK

The following summary of the terms of our common stock is not complete. You should refer to the applicable provision of our Restated Certificate of Incorporation and to the Delaware General Corporation Law for a complete statement of the terms and rights of the common stock.

General

We have authorized 560,000,000 shares of common stock, par value $1.66 2/3 per share. As of June 30, 2017, there were 228,485,957 shares of common stock outstanding. The outstanding shares of common stock are listed on the NASDAQ Global Select Market under the symbol “NTRS.”

Voting

Holders of common stock vote as a single class on all matters submitted to a vote of the stockholders with each share of common stock entitled to one vote. Holders of common stock do not have cumulative voting rights.

Dividends

Holders of common stock are entitled to receive the dividends that may be declared from time to time by the board of directors. The rights of holders of common stock to receive dividends are subject to the prior rights of holders of any issued and outstanding preferred stock. You should carefully read and consider the information regarding certain dividend restrictions to which we are subject in the “Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities” section of our most recent Annual Report on Form 10-K, which is incorporated by reference in this prospectus.

Other Provisions

Upon voluntary or involuntary liquidation, dissolution, or winding up of the Corporation, the holders of the common stock are entitled to receive, pro rata according to the number of shares held by each, all of our assets remaining for distribution after payment to creditors and the holders of any issued and outstanding preferred stock of the full preferential amounts to which they are entitled. The common stock has no preemptive or other subscription rights, and there are no other conversion rights or redemption provisions with respect to the shares.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Wells Fargo Bank, N.A.

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DESCRIPTION OF THE STOCK PURCHASE CONTRACTS AND STOCK PURCHASE UNITS

We may issue stock purchase contracts, including contracts obligating holders to purchase from or sell to us, and us to sell to or purchase from the holders, a specified number of shares of our common stock, preferred stock, depositary shares or other securities at a future date or dates, which we refer to in this prospectus as stock purchase contracts. The price per unit of securities and the number of securities may be fixed at the time the stock purchase contracts are issued or may be determined by reference to a specific formula set forth in the stock purchase contracts and may be subject to anti-dilution formulas. The stock purchase contracts may be issued separately or as part of units, which we refer to in this prospectus as stock purchase units, consisting of a stock purchase contract and beneficial interests in the following or any combination thereof:

The beneficial interests comprising a part of a stock purchase unit may secure the holders’ obligations to purchase or sell the securities under the stock purchase contracts.

The stock purchase contracts may require us to make periodic payments to the holders of the stock purchase contracts or for the holders to make periodic payments to us. These payments may be unsecured or prefunded on some basis. Our obligation to settle pre-paid stock purchase contracts on the relevant settlement date may constitute indebtedness. The stock purchase contracts may require holders to secure their obligations under those contracts in a specified manner.

If we issue stock purchase contracts or stock purchase units, the applicable prospectus supplement will describe the terms of the stock purchase contracts or stock purchase units, including:

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DESCRIPTION OF THE WARRANTS

We may issue warrants to purchase debt securities, preferred stock, depositary shares, common stock or other securities. We may offer warrants separately or together with one or more additional warrants, debt securities, shares of preferred or common stock, depositary shares or other securities, or any combination of those securities in the form of units, as described in the applicable prospectus supplement. If we issue warrants as part of a unit, the applicable prospectus supplement will specify whether those warrants may be separated from the other securities in the unit prior to the warrants’ expiration date. We will issue the warrants under one or more warrant agreements to be entered into between us and a bank or trust company, as warrant agent, all as described in the applicable prospectus supplement. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants.

We will describe the particular terms of any warrants that we offer in the prospectus supplement relating to those warrants. Those terms may include the following:

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PLAN OF DISTRIBUTION

We may offer and sell the securities described in this prospectus through underwriters, through dealers, through agents, directly to purchasers, through or in connection with hedging transactions, or through any combination of such methods of sale and may do so at a fixed price or prices (which may be changed), at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices. In addition, we may issue securities as a dividend or distribution, in a subscription rights offering to our existing securityholders.

Each time we sell securities, we will provide a prospectus supplement that will describe the method of distribution of the securities and name any underwriter, dealer or agent involved in the offer and sale. The prospectus supplement will also set forth the terms of the offering, including the purchase price of the securities and the proceeds we will receive from the sale of the securities, any underwriting discounts and other items constituting underwriters’ compensation related to the offering, public offering or purchase price and any discounts or commissions allowed or paid to dealers, any commissions allowed or paid to agents and any securities exchanges on which the securities may be listed.

Distribution Through Underwriters

We may offer and sell securities from time to time to one or more underwriters who would purchase the securities as principal for resale to the public, either on a firm commitment or best efforts basis. If the securities are sold to underwriters, we will execute an underwriting agreement with them at the time of the sale and we will name them in the applicable prospectus supplement. In connection with these sales, the underwriters will receive compensation in the form of underwriting commissions, which will be paid by us. The underwriters also may receive commissions from purchasers of securities for whom they may act as agent. Unless we specify otherwise in the applicable prospectus supplement, the underwriters will not be obligated to purchase the securities unless the conditions set forth in the underwriting agreement are satisfied, and if the underwriters purchase any of the securities, they will be required to purchase all of the offered securities. The underwriters may acquire the securities for their own account and may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or varying prices determined at the time of sale. The underwriters may sell the offered securities to or through dealers, and those dealers may receive discounts, concessions or commissions from the underwriters as well as from the purchasers for whom they may act as agent. Any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

Distribution Through Dealers

We may offer and sell securities from time to time to one or more dealers who would purchase the securities as principal. The dealers then may resell the offered securities to the public at fixed or varying prices to be determined by the dealers at the time of resale. We will set forth the names of the dealers and the terms of the transaction in the applicable prospectus supplement.

Distribution Through Agents

We may offer and sell securities through agents that become parties to a distribution agreement. We will name any agent involved in the offer and sale and describe any commissions payable by us in the applicable prospectus supplement. Unless we specify otherwise in the applicable prospectus supplement, the agent will be acting on a best efforts basis during the appointment period.

Direct Sales

We may sell directly to, and solicit offers directly from, one or more purchasers without the involvement of any underwriters, dealers or agents. We will describe the terms of any sales of this kind in the prospectus supplement relating to the offer.

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General

In connection with offerings made through underwriters or agents, we may enter into agreements with such underwriters or agents pursuant to which we receive our outstanding securities in consideration for the securities being offered to the public for cash. In connection with these arrangements, the underwriters or agents may also sell securities covered by this prospectus to hedge their positions in these outstanding securities, including in short sale transactions. If so, the underwriters or agents may use the securities received from us under these arrangements to close out any related open borrowings of securities.

We may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and will be identified in the applicable prospectus supplement or a post-effective amendment to the registration statement of which this prospectus forms a part.

We may loan or pledge securities to a financial institution or other third party that in turn may sell the securities using this prospectus. Such financial institution or third party may transfer its short position to investors in our securities or in connection with a simultaneous offering of other securities offered by this prospectus.

If indicated in the applicable prospectus supplement, we will authorize underwriters, dealers or agents to solicit offers by certain institutional investors to purchase securities from us pursuant to contracts providing for payment and delivery at a future date. In all cases, these purchasers must be approved by us. Unless otherwise set forth in the applicable prospectus supplement, the obligations of any purchaser under any of these contracts will not be subject to any conditions except that (i) the purchase of the securities must not at the time of delivery be prohibited under the laws of any jurisdiction to which that purchaser is subject and (ii) if the securities are also being sold to underwriters, we must have sold to these underwriters the securities not subject to delayed delivery. Underwriters and other agents will not have any responsibility in respect of the validity or performance of these contracts.

Underwriters, dealers, agents and other persons may be entitled under agreements which may be entered into with us to indemnification against and contribution toward certain civil liabilities, including liabilities under the Securities Act and to be reimbursed by us for certain expenses.

Subject to any restrictions relating to debt securities in bearer form, any securities initially sold outside the United States may be resold in the United States through underwriters, dealers or otherwise.

Securities other than common stock may represent a new issue of securities with no established trading market. Any underwriters to whom offered securities are sold by us for public offering and sale may make a market in such securities, but such underwriters will not be obligated to do so and may discontinue any market making at any time.

The anticipated date of delivery of the securities offered by this prospectus will be described in the applicable prospectus supplement. The securities offered by this prospectus may or may not be listed on a national securities exchange or a foreign securities exchange. No assurance can be given as to the liquidity or activity of any trading in the offered securities.

In connection with an underwritten offering, the underwriters may engage in over-allotment, stabilizing transactions and syndicate covering transactions in accordance with Regulation M under the Exchange Act.

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Over-allotment involves sales in excess of the offering size, which creates a short position for the underwriters. The underwriters may enter bids for, and purchase, securities in the open market in order to stabilize the price of the securities. Syndicate covering transactions involve purchases of the securities in the open market after the distribution has been completed in order to cover short positions. In addition, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions, or otherwise. These activities may cause the price of the securities to be higher than it would otherwise be. Those activities, if commenced, may be discontinued at any time.

Under Rule 15c6-1 of the SEC under the Exchange Act, trades in the secondary market generally are required to settle on the third business day following the trade date unless the parties to any such trade expressly agree otherwise. Commencing September 5, 2017, trades in the secondary market generally will be required to settle on the second business day following the trade date unless the parties to any such trade expressly agree otherwise. It is possible that we or any underwriter, dealer or agent selling our securities in reliance on this prospectus will elect to settle the sale of securities offered and sold in reliance on this prospectus in accordance with a longer than standard settlement cycle, in which case the alternative settlement cycle to be used will be specified in the applicable prospectus supplement. In the event such a longer than standard settlement cycle is elected, purchasers who desire to effect a trade of the securities they purchase at any time prior to the third business day (or, on or after September 5, 2017, the second business day) preceding the issue date of such securities will be required to specify an alternative settlement cycle at the time of any such trade to prevent a failed settlement. Any such purchasers of securities who desire to trade on any such day should consult their own advisers regarding the date on which such purchasers’ trades may be settled.

The underwriters, agents, dealers and their affiliates may engage in financial or other business transactions with us and our subsidiaries in the ordinary course of business.

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LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, the validity of the securities offered by this prospectus will be passed upon for us by Mayer Brown LLP, Chicago, Illinois. Certain legal matters will be passed upon for any underwriters, dealers or agents by counsel named in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of Northern Trust Corporation and subsidiaries as of December 31, 2016 and 2015, and for each of the years in the three-year period ended December 31, 2016, and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2016, which are included in our Annual Report on Form 10-K, have been incorporated by reference herein in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

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$                         

Northern Trust Corporation

% Senior Notes due

PROSPECTUS SUPPLEMENT

Joint Book-Running Managers

Morgan Stanley

BofA Securities

Goldman Sachs & Co. LLC

Wells Fargo Securities

                , 2020