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                                                                     EXHIBIT 5.1



                                October 24, 2000


Triton Energy Limited
Caledonian House
Jennett Street
P.O. Box 1043
George Town
Grand Cayman, Cayman Islands

Ladies and Gentlemen:

         We have acted as counsel for Triton Energy Limited, a Cayman Islands
company (the "Company"), in connection with the exchange of $300,000,000
aggregate principal amount of the Company's 8 7/8% Senior Subordinated Notes due
2007 (the "New Notes") for $300,000,000 aggregate principal amount of the
Company's 8 7/8% Senior Subordinated Notes due 2007 (the "Old Notes"). The New
Notes are to be exchanged for the Old Notes in a registered exchange offer (the
"Exchange Offer") pursuant to the Registration Rights Agreement dated October 4,
2000 (the "Registration Rights Agreement"), among the Company, Chase Securities
Inc., Merrill Lynch Pierce, Fenner & Smith Incorporated, Goldman, Sachs & Co.,
Banc of America Securities LLC, Barclays Capital, and Deutsche Banc Alex. Brown.

         The Old Notes have been, and the New Notes will be, issued pursuant to
an Indenture dated as of October 4, 2000 (the "Indenture"), between the Company
and The Chase Manhattan Bank, a New York banking corporation, as Trustee (the
"Trustee"). Unless the context otherwise requires, each capitalized term used
and not defined herein shall have the meaning given such term in the Indenture.

         In reaching the opinion set forth herein, we have reviewed originals or
copies of the Indenture, the Registration Rights Agreement, the Registration
Statement on Form S-4 filed by the Company under the Securities Act of 1933
registering the offering of the New Notes (the "Registration Statement"), and
such other documents and matters of law that we deemed relevant.

         Based upon the foregoing, and subject to the assumptions and
qualifications hereinafter stated, we express the opinion that the New Notes,
when duly executed, authenticated, issued and delivered in accordance with the
Exchange Offer and the Indenture, and when delivered in exchange for the Old
Notes, will constitute valid and binding obligations of the Company entitled to
the benefits of the Indenture, subject to (i) laws relating to bankruptcy,
insolvency, fraudulent conveyance, fraudulent



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Triton Energy Limited
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October 24, 2000


transfer, reorganization, rearrangement, liquidation, conservatorship,
moratorium and other laws affecting the enforcement of creditors' rights or the
collection of debtors' obligations generally, (ii) principles of equity
(regardless of whether enforceability is considered in a proceeding in equity or
at law) and (iii) an implied covenant of good faith and fair dealing.

         For purposes of this opinion,  we have assumed that (i) all information
contained in all documents reviewed by us is true and correct, (ii) all
signatures on all documents reviewed by us are genuine, (iii) all documents
submitted to us as originals are true and complete, (iv) all documents submitted
to us as copies are true and complete copies of the originals thereof, (v) each
natural person signing any document reviewed by us had the legal capacity to do
so, and (vi) each person signing any document reviewed by us in a representative
capacity had authority to sign in such capacity.

         This opinion may be filed as an exhibit to the Registration Statement.
Consent is also given to the reference to this firm under the caption "Legal
Matters" in the Prospectus included in the Registration Statement as having
passed on certain legal matters in connection with the Notes. In giving this
consent we do not admit that we come within the category of persons whose
consent is required under Section 7 of the Securities Act or the rules and
regulations of the Securities and Exchange Commission promulgated thereunder.

         We express no opinion as to any matter other than as expressly set
forth above, and no opinion on any other matter may be inferred or implied
herefrom. The opinion expressed herein is given as of the date hereof, and we
undertake no, and hereby disclaim any, obligation to advise you of any change in
any matter set forth herein. The opinion expressed herein is for the sole use
and benefit of, and may only be relied upon by, the Company, and is not to be
used, circulated, quoted or otherwise referred to in connection with any
transaction other than the Exchange Offer or by or to any other person without
our prior written consent.

                                Very truly yours,




                                /s/ Vinson & Elkins L.L.P.