Exhibit 5.1

                     [Letterhead of Davis Polk & Wardwell]


                                                              September 7, 2001

International Paper Company
400 Atlantic Street
Stamford, Connecticut 06921

Ladies and Gentlemen:

      We have acted as counsel for International Paper Company, a corporation
organized and existing under the laws of the State of New York (the "Company")
in connection with the preparation and filing of a Registration Statement on
Form S-3 with the Securities and Exchange Commission under the Securities Act
of 1933, as amended (the "Registration Statement") and the accompanying
prospectus (the "Prospectus") pertaining to the offer and sale by the selling
securityholders named or to be named therein of up to $2,105,000,000 aggregate
principal amount at maturity of the Company's Zero Coupon Convertible
Debentures due June 20, 2021 (the "Debentures") and the shares of common stock
of the Company issuable upon conversion of the Debentures (the "Common Stock").

      We have examined originals or copies, certified or otherwise identified
to our satisfaction, of such documents, corporate records, certificates of
public officials and other instruments as we have deemed necessary or advisable
for the purpose of rendering this opinion.

      Upon the basis of the foregoing and subject to the qualifications set
forth below, we are of the opinion that:

     (i)  the Debentures have been legally and validly issued and are binding
          obligations of the Company, enforceable in accordance with their
          terms, subject to applicable bankruptcy, insolvency or similar laws
          affecting creditors' rights generally and general principles of
          equity; and

     (ii) with respect to Common Stock, when certificates representing the
          Common Stock have been duly executed, countersigned, registered and
          delivered upon conversion of the Debentures as contemplated in the
          Registration Statement, the Common Stock will be duly authorized,
          validly issued, fully paid and non-assessable.

      We hereby consent to the reference to us under the caption "Legal
Matters" in the Prospectus forming a part of the Registration Statement and to
the filing of this opinion as an exhibit to the Registration Statement.

                                                       Very truly yours,

                                                       /s/ Davis Polk & Wardwell