Frontier (ULCC) S-4/A Registration of securities issued in business combination transactions (amended)

Exhibit 5.1

	140 Scott Drive
	Menlo Park, California 94025
	Tel: +1.650.328.4600 Fax: +1.650.463.2600
	www.lw.com
	FIRM / AFFILIATE OFFICES
	Austin	Moscow
	Beijing	Munich
	Boston	New York
	Brussels	Orange County
	Century City	Paris
April 15, 2022	Chicago	Riyadh
	Dubai	San Diego
	Düsseldorf	San Francisco
	Frankfurt	Seoul
	Hamburg	Shanghai
	Hong Kong	Silicon Valley
	Houston	Singapore
Frontier Group Holdings, Inc.	London	Tel Aviv
4545 Airport Way	Los Angeles	Tokyo
Denver CO, 80239	Madrid	Washington, D.C.
	Milan

Re: Registration Statement on Form S-4;

Shares of Voting Common Stock, par value $0.001 per share, of Frontier Group Holdings, Inc.

To the addressee set forth above:

We have acted as counsel to Frontier Group Holdings, Inc., a Delaware corporation (the “Company”), in connection with the proposed issuance of up to 215,492,296 shares of voting common stock, par value $0.001 per share, of the Company (the “Shares”), pursuant to the terms and conditions of the Agreement and Plan of Merger (the “Merger Agreement”), dated as of February 5, 2022, by and among the Company, Spirit Airlines, Inc., a Delaware corporation (“Spirit”), and Top Gun Acquisition Corp., a Delaware corporation and a direct wholly owned subsidiary of Frontier. The Shares are included in a registration statement on Form S-4 under the Securities Act of 1933, as amended (the “Act”), filed with the Securities and Exchange Commission (the “Commission”) on April 15, 2022 (the “Registration Statement”). 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 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 (the “DGCL”), and we express no opinion with respect to any other laws.

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, when the Shares shall have been duly registered on the books of the transfer agent and registrar therefor in the name or on behalf of the applicable Spirit stockholders, and have been issued by the Company against payment therefor (not less than par value) in the circumstances contemplated by the Registration Statement and the Merger Agreement, the issue and sale of the Shares will have been duly authorized by all necessary corporate action of the Company, and the Shares will be validly issued, fully paid and nonassessable.

April 15, 2022

Page  2

In rendering the foregoing opinion, we have assumed that (i) prior to the delivery of any Shares, the Registration Statement will have been declared effective under the Act, that the registration will apply to all of the Shares and will not have been modified or rescinded, and that there will not have occurred any change in law affecting the validity of the issuance of such Shares, and (ii) the Company will comply with all applicable notice requirements regarding uncertificated shares provided in the DGCL.

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 in the Prospectus under the heading “Legal Matters.” We further consent to the incorporation by reference of this letter and consent into any registration statement or post-effective amendment to the Registration Statement filed pursuant to Rule 462(b) with respect to the Shares. 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