September 13, 2005

Mail Stop 4561

By U.S. Mail and facsimile to (312) 630-6739

William A. Osborn
Chief Executive Officer
Northern Trust Corporation
Fifty South LaSalle Street
Chicago, IL 60675

	Re:	Northern Trust Corporation
		Form 10-K for Fiscal Year Ended December 31, 2004
		Filed March 14, 2005
		File No. 0-05965

Dear Mr. Osborn:

	We have reviewed the above referenced filing, and have the
following comments. We have limited our review to only the issues
raised in our comments.   Where indicated, we think you should
revise
future filings in response to these comments.  If you disagree, we
will consider your explanation as to why our comments are
inapplicable or a revision is unnecessary.  Please be as detailed
as
necessary in your explanation.  In our comments, we may ask you to
provide us with supplemental information so we may better
understand
your disclosure.  After reviewing this information, we may or may
not
raise additional comments.

	Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or any other aspect
of
our review.  Feel free to call us at the telephone numbers listed
at
the end of this letter.

Financial Statements

Note 18 - Other Operating Income and Expenses, page 83

1. We note your disclosure that other income in 2002 included
gains
of $8.5 million from the sale of leased equipment at the end of
the
scheduled lease terms and a $4.6 million write-off of the residual
value of an aircraft leased to United Airlines. Please provide the
following information to us relating to your leasing activities:

* Tell us to what extent you engage in leasing activities and
describes the types and classification of leases to which you are
a
party.

* Tell us how you determine the residual values of leased assets
at
the end of the lease term.

* Tell us how often you evaluate the residual value of leased
assets
for impairment.

* Specifically explain how you determined the gains and losses
recognized in 2002 related to the sale of leased equipment and the
write-off of the leased aircraft.

Note 24 - Contingent Liabilities, page 90

2. You disclose that you and one of your subsidiaries are named as
a
defendant in several Enron-related class action suits.  Please
tell
us and revise future filings to disclose the possible range of
loss
that may result from your lawsuits, or explain why you cannot
estimate a range of possible loss. Refer to paragraph 10 of SFAS
5.

Note 25 - Derivative Financial Instruments, page 91

3. Given the significance of derivatives to your risk management
objectives and the multitude of derivative instruments that you
use,
please tell us and revise future filings to more clearly describe
your objectives for holding or issuing such instruments.  Consider
providing the following information in a tabular format to
summarize
your hedging strategies:

* Identify each type of asset or liability for which you employ
hedging strategies;

* Identify the types of market risk associated with each asset or
liability identified above;

* Identify the financial instruments, including the types of
derivatives, which you use to manage each of these risks;

* Disclose the hedging classification for each derivative
instrument;
and

* Identify whether you use the long-haul method, the short-cut
method, or matched terms to assess the effectiveness of each
hedging
strategy.

*    *    *    *

      As appropriate, please respond to these comments within 10
business days or tell us when you will provide us with a response.
Please furnish a cover letter that keys your responses to our
comments and provides any requested supplemental information.
Detailed cover letters greatly facilitate our review.  Please
understand that we may have additional comments after reviewing
your
responses to our comments.

	We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filing reviewed by the staff to
be
certain that they have provided all information investors require
for
an informed decision.  Since the company and its management are in
possession of all facts relating to a company`s disclosure, they
are
responsible for the accuracy and adequacy of the disclosures they
have made.

	In connection with responding to our comments, please
provide,
in writing, a statement from the company acknowledging that:

* the company is responsible for the adequacy and accuracy of the
disclosure in the filing;

* staff comments or changes to disclosure in response to staff
comments do not foreclose the Commission from taking any action
with
respect to the filing; and

* the company may not assert staff comments as a defense in any
proceeding initiated by the Commission or any person under the
federal securities laws of the United States.

      In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division of Corporation Finance in our review of your filing or in
response to our comments on your filing.

      You may contact Isa Farhat at (202) 551-3485 or me at (202)
551-3246 if you have questions regarding our comments.



      Sincerely,


						Angela Jackson
						Senior Accountant


William A. Osborn
Northern Trust Corporation
September 13, 2005
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