EXHIBIT 5.1








                                           June 13, 2002


USA Interactive
152 West 57th Street, 42nd Floor
New York, NY 10019

Ladies and Gentlemen:

                  We have acted as counsel to USA Interactive, a Delaware
corporation (the Company"), in connection with the preparation and filing of the
Registration Statement on Form S-3 of the Company (as amended, the "Registration
Statement") under the Securities Act of 1933, as amended (the "Act"), relating
to the resale of up to 11,805,555 shares of the Company's common stock, par
value $.01 per share (the "Shares"), to be issued by the Company pursuant to the
Agreement and Plan of Merger dated as of May 30, 2002 (the "Merger Agreement"),
among the Company, Interval Acquisition Corp., a Delaware corporation
("Interval"), I Exchange Merger Corp., a Delaware corporation, and certain
stockholders of Interval who are signatories thereto.

                  We have reviewed such corporate records, certificates and
other documents, and such questions of law, as we have considered necessary or
appropriate for the purposes of this opinion. We have assumed that all
signatures are genuine, that all documents submitted to us as originals are
authentic, and that all copies of documents submitted to us conform to the
originals.

                  We have relied as to certain matters on information obtained
from public officials, officers of the Company and other sources believed by us
to be responsible.

                  Based upon the foregoing, and subject to the qualifications
set forth below, we are of the opinion that the Shares have been duly
authorized, and, when the Registration Statement has been declared effective by
order of the Securities and Exchange Commission and the Shares have been issued
and delivered to and paid for by the stockholders of Interval pursuant to the
Merger Agreement, and assuming compliance with the Act, will be legally issued,
fully paid and nonassessable.

                  We are members of the bar of the State of New York. We do not
purport to be experts in, and do not express any opinion on, any laws other than
the law of the State of New York, the Delaware General Corporation Law and the
Federal law of the United States of America.



USA Interactive
June 13, 2002
Page 2

                  We hereby consent to the filing of this opinion as Exhibit 5.1
to the Registration Statement and to the reference to our firm under the heading
"Legal Matters" in the Prospectus contained in the Registration Statement. In
giving such consent, we do not thereby admit that we are in the category of
persons whose consent is required under Section 7 of the Securities Act.

                                           Very truly yours,



                                           /s/ COVINGTON & BURLING