Exhibit 5.1

Rachel B. Proffitt
+1 415 693 2031
rproffitt@cooley.com

April 12, 2022

Xos, Inc.

3550 Tyburn Street

Los Angeles, CA 90065

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection with the issuance and sale by Xos, Inc., a Delaware corporation (the “Company”) of (i) 16,160,214 shares (the “Commitment Shares”) of the Company’s common stock, par value $0.0001 per share (“Common Stock”), and (ii) additional shares of Common Stock having aggregate sales proceeds of up to $125,000,000 (the “Advance Shares”), pursuant to a Registration Statement on Form S-1 (the “Registration Statement”) filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”), the related prospectus included in the Registration Statement (the “Prospectus”). The Commitment Shares were issued and the Advance Shares are to be sold by the Company pursuant to that certain Standby Equity Purchase Agreement, dated as of March 23, 2022 (the “Purchase Agreement”), by and between the Company and YA II PN, Ltd.

In connection with this opinion, we have examined and relied upon (a) the Registration Statement and the Prospectus, (b) the Purchase Agreement, (c) the Company’s certificate of incorporation and bylaws, each as currently in effect, and (d) originals or copies certified to our satisfaction, of such records, documents, certificates, opinions, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies; the accuracy, completeness and authenticity of certificates of public officials and the due authorization, execution and delivery of all documents by all persons other than the Company where due execution and delivery are a prerequisite to the effectiveness thereof. As to certain factual matters, we have relied upon a certificate of an officer of the Company and have not independently verified such matters.

We have assumed (i) each sale of the Advance Shares will be duly authorized by the Board of Directors of the Company, a duly authorized committee thereof or a person or body pursuant to an authorization granted in accordance with Section 152 of the General Corporation Law of the State of Delaware (the “DGCL”) and (ii) that no more than 16,160,214 Advance Shares will be sold. We express no opinion to the extent that future issuances of securities of the Company and/or anti-dilution adjustments to outstanding securities of the Company cause the number of shares of Common Stock outstanding or issuable upon conversion or exercise of outstanding securities of the Company to exceed the number of Advance Shares then issuable under the Purchase Agreement.

Cooley LLP 3 Embarcadero Center 20th Floor San Francisco, CA 94111-4004
t: +1 415 693 2000 f: +1 415 693 2222 cooley.com

Xos, Inc.

April 12, 2022

Page Two

Our opinion herein is expressed solely with respect to the DGCL. We express no opinion to the extent that any other laws are applicable to the subject matter hereof and express no opinion and provide no assurance as to compliance with any federal or state securities law, rule or regulation.

On the basis of the foregoing and in reliance thereon, and subject to the qualifications herein stated, we are of the opinion that (i) the Commitment Shares have been validly issued and are fully paid and nonassessable and (ii) the Advance Shares, when sold and issued in accordance with the Registration Statement, the Prospectus and the Purchase Agreement, will be validly issued, fully paid and nonassessable.

We consent to the reference to our firm under the caption “Legal Matters” in the Prospectus and to the filing of this opinion as an exhibit to the Registration Statement.

Very truly yours,

Cooley LLP
By:	/s/ Rachel Proffitt
	Rachel B. Proffitt

Cooley LLP 3 Embarcadero Center 20th Floor San Francisco, CA 94111-4004
t: +1 415 693 2000 f: +1 415 693 2222 cooley.com