UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 12b-25

NOTIFICATION OF LATE FILING

(Check One): ¨ Form 10-K    ¨ Form 20-F    ¨ Form 11-K    x Form 10-Q    ¨ Form 10-D    ¨ Form N-SAR    ¨ Form N-CSR

For Period Ended: December 31, 2015

¨   Transition Report on Form 10-K
¨   Transition Report on Form 20-F
¨   Transition Report on Form 11-K
¨   Transition Report on Form 10-Q
¨   Transition Report on Form N-SAR

For the Transition Period Ended: ___________________

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:

PART I — REGISTRANT INFORMATION

PART II — RULES 12b-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

PART III — NARRATIVE

State below in reasonable detail why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-SAR, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

Energy XXI Ltd (the “Company”) is unable to file its Quarterly Report on Form 10-Q for the period ended December 31, 2015 (the “Form 10-Q”) by the prescribed due date as a result of unexpected delays in the completion of its financial statements and related portions of its Form 10-Q due to the continued evaluation of the Company’s proved reserves in light of continued depressed commodity prices and current market conditions. Any write-down of the Company’s reserves would impact, among other items, its depreciation, depletion and amortization, impairment and asset retirement obligation calculations. The Company is working diligently to address these issues and anticipates that the Form 10-Q will be filed on or before the fifth calendar day following its prescribed due date, although there can be no assurance in this regard.

PART IV — OTHER INFORMATION

If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

Cautionary Note to Investors Regarding Forward-Looking Statements

This Notification of Late Filing on Form 12b-25 contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements include, among other things, the statement that the Company expects to file the Form 10-Q on or before the fifth calendar day following its prescribed due date. There can be no assurance that the Company will be able to file the Form 10-Q within that time period or that such estimates will not change. Forward-looking statements are subject to a number of uncertainties and risks, and actual results may differ materially from those projected. Factors that could affect the Company's actual results include unanticipated delays in the conclusion of the Company’s preparation of the financial statements described above and the effects of other various risk factors and uncertainties disclosed in the Company’s filings with the Securities and Exchange Commission, especially on Forms 10-K, 10-Q and 8-K. Such forward-looking statements are made only as of the date of this Notification of Late Filing on Form 12b-25, and the Company does not undertake any obligation to update any forward-looking statement to reflect subsequent events or circumstances except to the extent required by applicable law.

has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.

INSTRUCTION: The form may be signed by an executive officer of the registrant or by any other duly authorized representative. The name and title of the person signing the form shall be typed or printed beneath the signature. If the statement is signed on behalf of the registrant by an authorized representative (other than an executive officer), evidence of the representative’s authority to sign on behalf of the registrant shall be filed with the form.