Exhibit 5.1

	811 Main Street, Suite 3700
	Houston, TX 77002
	Tel: +1.713.546.5400   Fax: +1.713.546.5401
	www.lw.com
	FIRM / AFFILIATE OFFICES
	Austin	Milan
	Beijing	Munich
	Boston	New York
	Brussels	Orange County
	Century City	Paris
August 15, 2023	Chicago	Riyadh
	Dubai	San Diego
	Dusseldorf	San Francisco
	Frankfurt	Seoul
	Hamburg	Shanghai
	Hong Kong	Silicon Valley
	Houston	Singapore
	London	Tel Aviv
	Los Angeles	Tokyo
	Madrid	Washington, D.C.

NextDecade Corporation

1000 Louisiana Street, Suite 3900

Houston, Texas 77002

Re:         Registration Statement on Form S-3

To the addressee set forth above:

We have acted as special counsel to NextDecade Corporation, a Delaware corporation (the “Company”), in connection with its filing on the date hereof with the Securities and Exchange Commission (the “Commission”) of a registration statement on Form S‑3 (as amended, the “Registration Statement”), including a base prospectus (the “Base Prospectus”), which provides that it will be supplemented by one or more prospectus supplements (each such prospectus supplement, together with the Base Prospectus, a “Prospectus”), under the Securities Act of 1933, as amended (the “Act”), relating to the resale from time to time by the selling stockholders named in the Registration Statement of up to 24,163,042 shares (the “Shares”) of the Company’s common stock, $0.0001 par value per share (“Common Stock”), that are issued and outstanding as of the date hereof.

This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or related applicable Prospectus, other than as expressly stated herein with respect to the issue of the Shares.

As such counsel, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, we have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. We are opining herein as to the General Corporation Law of the State of Delaware, and we express no opinion with respect to the applicability thereto, or the effect thereon, of the laws of any other jurisdiction or, in the case of Delaware, any other laws, or as to any matters of municipal law or the laws of any local agencies within any state.

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, the Shares have been duly authorized by all necessary corporate action of the Company and are validly issued, fully paid and nonassessable.

This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Act. We consent to your filing this opinion as an exhibit to the Registration Statement and to the reference to our firm contained in the Prospectus under the heading “Legal Matters.” 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 Act or the rules and regulations of the Commission thereunder.

Sincerely,

/s/ Latham & Watkins LLP