Exhibit 5


                                      April 15, 1997



   Securities and Exchange Commission
   Judiciary Plaza 
   450 Fifth Street, N.W. 
   Washington, DC 20549-1004

        Re:  Northern Trust Corporation - Registration Statement on
             Form S-8

   Ladies and Gentlemen:

        I am Executive Vice President, General Counsel and Secretary of
   Northern Trust Corporation, a Delaware corporation (the
   "Corporation"), and have served in that capacity in connection with
   the Corporation s filing of a Registration Statement on Form S-8 (the
   "Registration Statement") with the Securities and Exchange Commission
   covering the registration of an additional 8,500,000 shares of the
   Corporation s common stock, $1.66 2/3 par value per share, including
   the associated Preferred Stock Purchase Rights (collectively, the
   "Stock"), issuable pursuant to the Northern Trust Corporation Amended
   1992 Incentive Stock Plan (the "Plan").

        In that connection, I have examined such documents and have made
   such factual and legal investigations as I have deemed necessary or
   appropriate for the purpose of this opinion.

        Based upon the foregoing, it is my opinion that those shares of
   Stock covered by the Registration Statement that are issued in
   accordance with the terms of the Plan will be legally issued, fully
   paid and non-assessable.

        I hereby consent to the filing of this opinion as Exhibit 5 to
   the Registration Statement.

                                 Very truly yours,



                                 By:  /s/ Peter L. Rossiter
                                      -----------------------------
                                      Peter L. Rossiter
                                      Executive Vice President, General
                                      Counsel and Secretary