Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
OSBORN WILLIAM A
  2. Issuer Name and Ticker or Trading Symbol
NORTHERN TRUST CORP [NTRS]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chairman and CEO
(Last)
(First)
(Middle)
50 S. LA SALLE ST.
3. Date of Earliest Transaction (Month/Day/Year)
10/20/2006
(Street)

CHICAGO, IL 60603
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 10/20/2006   M   46,468 A $ 28.3125 494,003 I By Trust
Common Stock 10/20/2006   F   9,256 D $ 57.185 484,747 I By Trust
Common Stock 10/20/2006   G V 4,382 D $ 0 480,365 I By Trust
Common Stock (1) 10/20/2006   F   515 (2) D $ 57.185 380,177 D  
Common Stock               78,445 (3) I 401(K)
Common Stock               37,055 I By Spouse
Common Stock               400 I Trustee of Mother's Trust

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Employee Stock Option (right-to-buy) $ 28.3125 10/20/2006   M     46,468 09/16/1999 09/16/2007 Common Stock 46,468 $ 0 100,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
OSBORN WILLIAM A
50 S. LA SALLE ST.
CHICAGO, IL 60603
  X     Chairman and CEO  

Signatures

 Eileen C. Ratzka POA for William A. Osborn   10/24/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Represents stock units payable automatically on a 1-for-1 basis in shares of the Corporation's common stock.
(2) 515 stock units withheld in payment of the taxes due upon the vesting of 22,000 stock units. Reporting person is deferring the distribution of 21,485 stock units.
(3) asof 9-30-06

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