EXHIBIT 5.1 May 25, 2001 Triton Energy Limited Caledonian House Jennett Street, P.O. Box 1043 George Town Grand Cayman, Cayman Islands Dear Sirs: This opinion is delivered in connection with the Registration Statement (the "Registration Statement") on Form S-8 filed with the Securities and Exchange Commission by Triton Energy Limited, a Cayman Islands company (the "Company"), under the Securities Act of 1933, as amended (the "Act"), relating to 1,000,000 of the Company's Ordinary Shares, par value $.01 per share (the "Shares"), issuable pursuant to the Company's 2001 Share Incentive Plan (the "Plan"). I am familiar with the Memorandum and Articles of Association of the Company, each as amended to date. In addition, I have examined such corporate records, documents and other instruments and have made such other examinations and inquiries as I have deemed necessary to enable me to express the opinions set forth herein. I am a member of the bar of the State of Texas and any opinion herein as to the laws of the Cayman Islands is based upon the latest generally available compilation of the statutes and case law of such jurisdiction. Based upon the foregoing, subject to the qualifications and limitations stated herein, and limited in all respects to the laws of the State of Texas, the Companies Law of the Cayman Islands and the laws of the United States of America, I am of the opinion that the Shares have been duly authorized and, when issued in accordance with the terms of the Plan, will be validly issued, fully paid and nonassessable. I hereby consent to the use of this opinion as an exhibit to the Registration Statement and the use of my name in Item 5 of the Registration Statement. Very truly yours, Triton Energy Limited By: /s/Thomas J. Murphy --------------------- Thomas J. Murphy, General Counsel