NORTHERN TRUST CORPORATION 3.950%Subordinated Notes due 2025

Exhibit 4.3

UNLESS THIS GLOBAL NOTE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), NEW YORK, NEW YORK, TO NORTHERN TRUST CORPORATION OR ITS AGENT OR AGENTS FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY GLOBAL NOTE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

TRANSFERS OF THIS GLOBAL NOTE SHALL BE LIMITED TO TRANSFERS IN WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR SUCH SUCCESSOR’S NOMINEE, AND TRANSFERS OF PORTIONS OF THIS GLOBAL NOTE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN THE INDENTURE REFERRED TO ON THE REVERSE HEREOF.

This Security is a Global Security within the meaning of the Indenture hereinafter referred to and is registered in the name of a Depositary or a nominee of a Depositary. This Security is exchangeable for Securities registered in the name of a person other than the Depositary or its nominee only in the limited circumstances described in the Indenture and may not be transferred except as a whole by the Depositary to a nominee of the Depositary or by a nominee of the Depositary to the Depositary or another nominee of the Depositary, except in the limited circumstances described in the Indenture.

NORTHERN TRUST CORPORATION

3.950% Subordinated Notes due 2025

NORTHERN TRUST CORPORATION, a corporation organized and existing under the laws of Delaware (hereinafter called the “Corporation”, which term includes any successor Person under the Indenture hereinafter referred to), for value received, hereby promises to pay to Cede & Co, or registered assigns, the principal sum of [            ] on October 30, 2025, or such other principal amount represented hereby as may be set forth in the records of the Securities Registrar hereinafter referred to in accordance with the Indenture. The Corporation further promises to pay interest on said principal sum from October 31, 2013 or from the most recent Interest Payment Date to which interest has been paid or duly provided for semi-annually in

arrears on April 30 and October 30 of each year, commencing April 30, 2014, at the rate of 3.950% per annum, until the principal hereof is paid or duly provided for or made available for payment The amount of interest payable for any period less than a full interest period shall be computed on the basis of a 360- day year of twelve 30-day months and the actual days elapsed in a partial month in such period. The amount of interest payable for any full interest period shall be computed by dividing the applicable rate per annum by two. The interest so payable, and punctually paid or duly provided for, on any Interest Payment Date will, as provided in the Indenture, be paid to the Person in whose name this Security (or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest installment, which shall be the 15th calendar day prior to such interest payment date (whether or not a Business Day), as the case may be, next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for shall forthwith cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security (or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than 10 days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture.

Payment of the principal of (and premium, if any) and interest (including any Additional Interest) on this Security will be made at the office or agency of the Corporation maintained for that purpose, or in such other office or agency as may be established by the Corporation pursuant to the Indenture (initially the principal corporate trust office of the Trustee in Chicago, Illinois), in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts.

The indebtedness evidenced by this Security is, to the extent provided in the Indenture, subordinate and junior in right of payment to the prior payment in full of all Senior Indebtedness, and this Security is issued subject to the provisions of the Indenture with respect thereto. Each Holder of this Security, by accepting the same, (a) agrees to and shall be bound by such provisions, (b) authorizes and directs the Trustee on his or her behalf to take such actions as may be necessary or appropriate to effectuate the subordination so provided, and (c) appoints the Trustee his or her attorney-in-fact for any and all such purposes. Each Holder hereof, by his or her acceptance hereof, waives all notice of the acceptance of the subordination provisions contained herein and in the Indenture by each holder of Senior Indebtedness, whether now outstanding or hereafter incurred, and waives reliance by each such holder upon said provisions.

Reference is hereby made to the further provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect as if set forth at this place.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

IN WITNESS WHEREOF, the Corporation has caused this instrument to be duly executed under its corporate seal.

TRUSTEE’S CERTIFICATE OF

AUTHENTICATION

This is one of the Securities of the series designated therein referred to in the within-mentioned Indenture.

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.,

as Trustee

This Security is one of a duly authorized issue of securities of the Corporation (herein called the “Securities”), issued and to be issued in one or more series under the Junior Subordinated Indenture, dated as of January 1, 1997 as amended by the First Supplemental Indenture, dated October 31, 2013 (herein called the “Indenture”), between the Corporation and The Bank of New York Mellon Trust Company, N.A. (as successor to First National Bank of Chicago, a national banking association), as Trustee (herein called the “Trustee”, which term includes any successor trustee under the Indenture), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Corporation, the Trustee, the holders of Senior Indebtedness and the Holders of the Securities, and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the series designated on the face hereof.

All terms used in this Security that are defined in the Indenture shall have the meanings assigned to them in the Indenture.

The Indenture contains provisions for satisfaction and discharge of the entire indebtedness of this Security upon compliance by the Corporation with certain conditions set forth in the Indenture.

The Indenture permits, with certain exceptions as therein provided, the Corporation and the Trustee at any time to enter into a supplemental indenture or indentures for the purpose of modifying in any manner the rights and obligations of the Corporation and of the Holders of the Securities, with the consent of the Holders of not less than a majority in principal amount of the Outstanding Securities of each series to be affected by such supplemental indenture. The Indenture also contains provisions permitting Holders of specified percentages in principal amount of the Securities of each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Corporation with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange herefor or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

As provided in and subject to the provisions of the Indenture, if an Event of Default with respect to the Securities of this series at the time Outstanding occurs and is continuing, then and in every such case the Trustee or the Holders of not less than 25% in aggregate principal amount of the Outstanding Securities of this series may declare the principal amount of all the Securities of this series to be due and payable immediately, by a notice in writing to the Corporation (and to the Trustee if given by Holders) and upon any such declaration the principal amount of and the accrued interest (including any Additional Interest) on all the Securities of this series shall become immediately due and payable, provided that the payment of principal and interest (including any Additional Interest) on such Securities shall remain subordinated to the extent provided in Article XIII of the Indenture.

No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Corporation, which is absolute and unconditional, to pay the principal of (and premium, if any) and interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the Securities Register, upon surrender of this Security for registration of transfer at the office or agency of the Corporation maintained under Section 10.2 of the Indenture for such purpose, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Corporation and the Securities Registrar duly executed by, the Holder hereof or such Holder’s attorney duly authorized in writing, and thereupon one or more new Securities of this series, of like tenor, of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.

The Securities of this series are issuable only in registered form without coupons in denominations of $2,000 principal amount and any integral multiple of $1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Corporation may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Security for registration of transfer, the Corporation, the Trustee and any agent of the Corporation or the Trustee may treat the Person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security be overdue, and neither the Corporation, the Trustee nor any such agent shall be affected by notice to the contrary.

The Corporation and, by its acceptance of this Security or a beneficial interest therein, the Holder of, and any Person that acquires a beneficial interest in, this Security agree that for United States federal, state and local tax purposes it is intended that this Security constitute indebtedness.

THIS SECURITY SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF ILLINOIS.