The Hain Celestial Group, Inc. (HAIN) 8-K Entry into a Material Definitive Agreement

Exhibit 5.1

November 15, 2021

The Hain Celestial Group, Inc.

Registration Statement on Form S-3

Ladies and Gentlemen:

We have acted as counsel to The Hain Celestial Group, Inc., a Delaware corporation (the “Company”), in connection with the preparation and filing with the Securities and Exchange Commission (the “Commission”) of a Registration Statement on Form S-3 (the “Registration Statement”) under the Securities Act of 1933, as amended (the “Securities Act”), relating to the registration under the Securities Act and the proposed issuance and sale from time to time pursuant to Rule 415 under the Securities Act of debt securities (“Debt Securities”) of the Company to be issued under an Indenture in the form included as Exhibit 4.1 to the Registration Statement (the “Indenture”) to be entered into between the Company and a trustee (the “Trustee”); preferred stock, par value $0.01 per share (the “Preferred Stock”) of the Company; common stock, par value $0.01 per share (the “Common Stock”) of the Company, including Common Stock as may from time to time be issued upon conversion of Debt Securities or Preferred Stock; depositary shares representing fractional or multiple shares of Preferred Stock (the “Depositary Shares”) of the Company; warrants to purchase Debt Securities, Preferred Stock or Common Stock (collectively, the “Warrants”) of the Company; stock purchase contracts (the “Stock Purchase Contracts”); and stock purchase units (the “Stock Purchase Units”). The Debt Securities, the Preferred Stock, the Depositary Shares, the Common Stock, the Warrants, the Stock Purchase Contracts and the Stock Purchase Units are collectively referred to herein as the “Securities”.

In connection with this opinion, we have examined originals, or copies certified or otherwise identified to our satisfaction, of such corporate records, certificates of corporate officers and government officials and such other documents as we have deemed necessary or appropriate for the purposes of this opinion, including: (a) the Restated Certificate of Incorporation of the Company; (b) the Amended and Restated Bylaws of the Company; (c) resolutions adopted by the board of directors of the

Company on November 6, 2021; (d) the Registration Statement; and (e) the Indenture. As to various questions of fact material to this opinion, we have relied upon representations of officers or directors of the Company and documents furnished to us by the Company without independent verification of their accuracy. We have also assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals and the conformity to authentic original documents of all documents submitted to us as copies.

Based upon and subject to the foregoing, and assuming that (i) the Registration Statement and any supplements and amendments thereto (including post-effective amendments) will have become effective and will comply with all applicable laws; (ii) the Registration Statement will be effective and will comply with all applicable laws at the time the Securities are offered or issued as contemplated by the Registration Statement; (iii) a prospectus supplement will have been prepared and filed with the Commission describing the Securities offered thereby and will comply with all applicable laws; (iv) all Securities will be issued and sold in compliance with all applicable Federal and state securities laws and in the manner stated in the Registration Statement and the appropriate prospectus supplement; (v) none of the terms of any Security to be established subsequent to the date hereof, nor the issuance and delivery of such Security, nor the compliance by the Company with the terms of such Security will violate any applicable law or will result in a violation of any provision of any instrument or agreement then binding upon the Company or any restriction imposed by any court or governmental body having jurisdiction over the Company; (vi) a definitive purchase, underwriting or similar agreement and any other necessary agreement with respect to any Securities offered or issued will have been duly authorized and validly executed and delivered by the Company and the other parties thereto; (vii) any deposit agreement, warrant agreement, Stock Purchase Contract or Stock Purchase Unit will be governed by the laws of the State of New York; and (viii) any Securities issuable upon conversion, exchange or exercise of any Security being offered or issued will be duly authorized, created and, if appropriate, reserved for issuance upon such conversion, exchange or exercise, we are of opinion that:

(1) with respect to Debt Securities to be issued under the Indenture, when (A) the Trustee has been qualified to act in such capacity under the Indenture, (B) the Trustee has duly executed and delivered the Indenture, (C) the Indenture has been duly authorized and validly executed and delivered by the Company to the Trustee, (D) the Indenture has been duly qualified under the Trust Indenture Act of 1939, as amended, (E) the board of directors of the Company, a duly constituted and acting committee thereof, or any officers of the Company delegated such authority (such board of directors, committee or officers being hereinafter referred to as the “Board”) has taken all necessary corporate action to approve the issuance and terms of a particular series of Debt Securities, the terms of the offering thereof, and related matters, and (F) such Debt Securities have been duly executed, authenticated, issued and delivered in accordance with the provisions of the Indenture,

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including any supplemental indenture or officer’s certificate related thereto, and the applicable definitive purchase, underwriting or similar agreement approved by the Board upon payment of the consideration therefor provided for therein, such Debt Securities will be validly issued and will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their terms (subject to applicable bankruptcy, insolvency, reorganization, fraudulent conveyance, moratorium or other similar laws affecting creditors’ rights generally from time to time in effect and subject to general principles of equity, including, without limitation, concepts of materiality, reasonableness, good faith and fair dealing, regardless of whether such enforceability is considered in a proceeding in equity or at law);

(2) with respect to shares of Preferred Stock, when (A) the Board has taken all necessary corporate action to approve the issuance and terms of a particular series of Preferred Stock, the terms of the offering thereof and related matters, including the adoption of a Certificate of Designation relating to such Preferred Stock (a “Certificate”) and the filing of such Certificate with the Secretary of State of the State of Delaware, (B) such Certificate has been properly filed with the Secretary of State of the State of Delaware and (C) certificates representing such shares of Preferred Stock have been duly executed, countersigned, registered and delivered either (i) in accordance with the applicable definitive purchase, underwriting or similar agreement approved by the Board upon payment of the consideration therefor (which consideration is not less than the par value of the Preferred Stock) provided for therein or (ii) upon conversion or exercise of any other Security, in accordance with the terms of such Security or the instrument governing such Security providing for such conversion or exercise as approved by the Board, for the consideration approved by the Board (which consideration is not less than the par value of the Preferred Stock), then such shares of Preferred Stock will be validly issued, fully paid and nonassessable;

(3) with respect to shares of Common Stock, when both (A) the Board has taken all necessary corporate action to approve the issuance of and the terms of the offering of (i) the Debt Securities or Preferred Stock, as the case may be, convertible or exchangeable into Common Stock or (ii) the shares of Common Stock, and related matters and (B) certificates representing the shares of Common Stock have been duly executed and countersigned (in the case of certificated shares), and such shares have been registered and delivered either (i) in accordance with the applicable definitive purchase, underwriting or similar agreement approved by the Board or such officers upon payment of the consideration therefor (which consideration is not less than the par value of the Common Stock) provided for therein or (ii) upon conversion or exercise of such Debt Security or Preferred Stock, as the case may be, in accordance with the terms of such security or the instrument governing such security providing for such conversion or exercise as approved by the Board, for the consideration approved by the Board (which consideration is not less than the par value of the Common Stock), then such shares of Common Stock will be validly issued, fully paid and nonassessable;

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(4) with respect to any Depositary Shares, when (A) the Board has taken all necessary corporate action to approve the creation of and the issuance and terms of the Depositary Shares and the related series of Preferred Stock, the terms of the offering thereof and related matters, (B) a deposit agreement or agreements relating to the Depositary Shares have been duly authorized and validly executed and delivered by the Company, the depositary appointed by the Company and each other party thereto, (C) the Certificate for the related series of Preferred Stock has been properly filed with the Secretary of State of the State of Delaware, (D) certificates representing such shares of Preferred Stock have been duly executed and countersigned (in the case of certificated shares), and such shares have been registered and delivered in accordance with the applicable definitive purchase, underwriting or similar agreement approved by the Board upon payment of the consideration therefor (which consideration is not less than the par value of the Preferred Stock) provided for therein and (E) Depositary Shares or receipts representing the Depositary Shares have been duly executed, countersigned, registered and delivered in accordance with the appropriate deposit agreement or agreements and the applicable definitive purchase, underwriting or similar agreement approved by the Board or such officers upon payment of the consideration therefor provided for therein, the Depositary Shares will be validly issued and will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their terms (subject to applicable bankruptcy, insolvency, reorganization, fraudulent conveyance, moratorium or other similar laws affecting creditors’ rights generally from time to time in effect and subject to general principles of equity, including, without limitation, concepts of materiality, reasonableness, good faith and fair dealing, regardless of whether such enforceability is considered in a proceeding in equity or at law);

(5) with respect to the Warrants, when (A) the Board has taken all necessary corporate action to approve the creation of and the issuance and terms of the Warrants, the terms of the offering thereof and related matters, (B) a warrant agreement or agreements relating to the Warrants have been duly authorized and validly executed and delivered by the Company, the warrant agent appointed by the Company and each other party thereto and (C) the Warrants or certificates representing the Warrants have been duly executed, countersigned, registered and delivered in accordance with the appropriate warrant agreement or

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agreements and the applicable definitive purchase, underwriting or similar agreement approved by the Board or such officers upon payment of the consideration therefor provided for therein, the Warrants will be validly issued and will constitute valid and binding obligations of the Company, enforceable against the Company in accordance with their terms (subject to applicable bankruptcy, insolvency, reorganization, fraudulent conveyance, moratorium or other similar laws affecting creditors’ rights generally from time to time in effect and subject to general principles of equity, including, without limitation, concepts of materiality, reasonableness, good faith and fair dealing, regardless of whether such enforceability is considered in a proceeding in equity or at law); and

(6) with respect to the Stock Purchase Contracts and/or the Stock Purchase Units, when (A) such Stock Purchase Contracts and/or Stock Purchase Units have been duly authorized, executed and delivered by the parties thereto, (B) the Board has taken all necessary corporate action to approve the creation of and the issuance and terms of such Stock Purchase Contracts and/or the Stock Purchase Units, the terms of the offering thereof and related matters, (C) if such Stock Purchase Units relate to the issuance and sale of Debt Securities, the actions described in paragraph 1 above have been taken, (D) if such Stock Purchase Contracts and/or Stock Purchase Units relate to the issuance and sale of shares of Common Stock, the actions described in paragraph 3 above have been taken, and (E) if such Stock Purchase Contracts and/or Stock Purchase relate to the issuance and sale of shares of Preferred Stock, the actions described in paragraph 2 above have been taken, then such Stock Purchase Contracts and/or the Stock Purchase Units will be legally issued and binding obligations of the Company (subject to applicable bankruptcy, insolvency, reorganization, fraudulent conveyance, moratorium, or other similar laws affecting creditors’ rights generally from time to time in effect and subject to general principles of equity, including concepts of materiality, reasonableness, good faith and fair dealing, regardless of whether such enforceability is considered in a proceeding in equity or at law).

We express no opinion herein as to any provision of the Indenture or the Debt Securities that (a) relates to the subject matter jurisdiction of any Federal court of the United States of America, or any Federal appellate court, to adjudicate any controversy related thereto, (b) contains a waiver of an inconvenient forum, (c) relates to the waiver of rights to jury trial or (d) provides for indemnification, contribution or limitations on liability. We also express no opinion as to (i) the enforceability of the provisions of the Indenture or the Debt Securities to the extent that such provisions constitute a waiver of illegality as a defense to performance of contract obligations or any other defense to performance which cannot, as a matter of law, be effectively waived or (ii) whether a state court outside the State of New York or a Federal court of the United States would give effect to the choice of New York law provided for therein.

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Courts in the United States have not customarily rendered judgments for money damages denominated in any currency other than United States dollars. Section 27(b) of the Judiciary Law of the State of New York provides, however, that a judgment or decree in an action based upon an obligation denominated in a currency other than United States dollars shall be rendered in the foreign currency of the underlying obligation and converted into United States dollars at the rate of exchange prevailing on the date of the entry of the judgment or decree. We express no opinion as to whether a Federal court of the United States would render a judgment other than in United States dollars.

We are admitted to practice only in the State of New York and express no opinion as to matters governed by any laws other than the laws of the State of New York, the Delaware General Corporation Law and the Federal laws of the United States of America.

We understand that we may be referred to as counsel who has passed upon the validity of the Debt Securities or the issuance of the Preferred Stock, Common Stock, Depositary Shares, Warrants, Stock Purchase Contracts or Stock Purchase Units on behalf of the Company in the prospectus and in a supplement to the prospectus forming a part of the Registration Statement relating to the Securities filed with the Commission pursuant to the Securities Act, and we hereby consent to such use of our name in said Registration Statement and to the use of this opinion for filing with said Registration Statement as Exhibit 5.1 thereto. In giving this consent, we do not hereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act or the Rules and Regulations of the Commission promulgated thereunder.

Very truly yours,

/s/ Cravath, Swaine & Moore LLP

The Hain Celestial Group, Inc.

1111 Marcus Avenue

Lake Success, New York 11042

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