EXHIBIT 5.1



                      [Letterhead of Robert N. Cowen, Esq.]






                                          June 15, 2001


Securities and Exchange Commission
Washington, D.C.  20549

Ladies and Gentlemen:

            I am Senior Vice President, Chief Operating Officer and General
Counsel of Overseas Shipholding Group, Inc., a Delaware corporation (the
"Company"), and I am rendering this opinion in connection with the Registration
Statement on Form S-3 (Registration No. 333-62702) (the "Registration
Statement") under the Securities Act of 1933 (the "Act") filed by the Company
with the Securities and Exchange Commission.

            The Registration Statement relates to the offering by certain
selling stockholders of up to 5,750,000 shares (the "Shares") of common stock,
par value $1.00 per share, of the Company.

            I have examined such records and documents and made such examination
of law as I have deemed relevant in connection with this opinion. Based upon
such examination, it is my opinion that the Shares are legally issued, fully
paid and non-assessable.

            I hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to me under the caption "Legal
Matters" in the Registration Statement. In so doing, I do not admit that I am in
the category of persons whose consent is required under Section 7 of the Act or
the rules and regulations of the Securities and Exchange Commission promulgated
thereunder.

                                          Very truly yours,


                                          /s/ Robert N. Cowen, Esq.