Exhibit 5.1

May 25, 2018

Cheniere Energy, Inc.

700 Milam Street, Suite 1900

Houston, Texas 77002

Ladies and Gentlemen:

We refer to the Registration Statement on Form S-3, File No. 333-225187 (the “Registration Statement”), filed by Cheniere Energy, Inc., a Delaware corporation (the “Company”), with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”), which Registration Statement became effective upon filing pursuant to Rule 462(e) under the Securities Act. Pursuant to the Registration Statement, the selling stockholders (the “Selling Stockholders”) are selling up to an aggregate of 10,278,739 shares (the “Shares”) of the Company’s common stock, $0.003 par value per share. A prospectus supplement dated May 25, 2018, relating to the offer and sale of the Shares, which, together with the prospectus filed with the Registration Statement (the “Base Prospectus”) constitute the “Prospectus,” was filed with the Commission pursuant to Rule 424(b)(7) (the “Prospectus Supplement’).

This opinion letter is being delivered in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act.

We have examined the Registration Statement, the Base Prospectus, the Prospectus Supplement, the Company’s certificate of incorporation, as amended, the by-laws of the Company, as amended, and the resolutions adopted by the board of directors of the Company relating to the Registration Statement and the issuance of the Shares by the Company. We have also examined originals, or copies of originals certified to our satisfaction, of such agreements, documents, certificates and statements of the Company and other corporate documents and instruments, and have examined such questions of law, as we have considered relevant and necessary as a basis for this opinion letter. We have assumed the authenticity of all documents submitted to us as originals, the genuineness of all signatures, the legal capacity of all persons and the conformity with the original documents of any copies thereof submitted to us for examination. As to facts relevant to the opinions expressed herein, we have relied without independent investigation or verification upon, and assumed the accuracy and completeness of, certificates, letters and oral and written statements and representations of public officials and officers and other representatives of the Company.

Based on and subject to the foregoing and the other limitations, qualifications and assumptions set forth herein, we are of the opinion that the Shares have been duly authorized and are validly issued, fully paid and non-assessable.

Sidley Austin LLP is a limited liability partnership practicing in affiliation with other Sidley Austin partnerships.

Cheniere Energy, Inc.

May 25, 2018

Page 2

This opinion letter is limited to the General Corporation Law of the State of Delaware. We express no opinion as to the laws, rules or regulations of any other jurisdiction, including, without limitation, the federal laws of the United States of America or any state securities or blue sky laws.

We hereby consent to the filing of this opinion letter as an Exhibit to the Registration Statement and to all references to our Firm included in or made a part of 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/ Sidley Austin