Document

Exhibit 5.1

Biohaven Ltd.

Kingston Chambers

P.O. Box 173

Road Town, Tortola

British Virgin Islands

5 October 2023

Dear Sirs

Biohaven Ltd. (the "Company")

We have acted as counsel as to British Virgin Islands law to the Company and have been asked to provide this legal opinion in connection with the Company's registration statement on Form S-3ASR, including all amendments or supplements thereto, including the Prospectus dated 2 October 2023, as supplemented by the Prospectus Supplement dated 2 October 2023 filed with the United States Securities and Exchange Commission (the "Commission") under the United States Securities Act of 1933, as amended (the "SEC Act") (including its exhibits, the "Registration Statement") in respect of the proposed issuance of 11,761,363 common shares of the Company of no par value each (the "Shares") pursuant to an underwriting agreement dated 2 October 2023 between the Company and J.P. Morgan Securities LLC.

1 Documents Reviewed

We have reviewed originals, copies, drafts or conformed copies of the following documents:

1.1 The public records of the Company on file and available for public inspection at the Registry of Corporate Affairs in the British Virgin Islands (the "Registry of Corporate Affairs") on 4 October 2023, including the Company's Certificate of Incorporation and its Memorandum and Articles of Association (the "Memorandum and Articles").

1.2 The records of proceedings available from a search of the electronic records maintained on the Judicial Enforcement Management System from 1 January 2000 and available for inspection on 2 October 2023 at the British Virgin Islands High Court Registry (the "High Court Registry").

1.3 The written resolutions of the board of directors of the Company dated 2 October 2023 (the "Resolutions").

1.4 A Certificate of Incumbency dated 29 September 2023, issued by Maples Corporate Services (BVI) Limited, the Company's registered agent (the "Registered Agent's Certificate").

1.5 A certificate of good standing with respect to the Company issued by the Registrar of Corporate Affairs dated 4 October 2023 (the "Certificate of Good Standing").

1.6 A certificate from a director of the Company (the "Director's Certificate").

1.7 The Registration Statement.

2 Assumptions

The following opinions are given only as to, and based on, circumstances and matters of fact existing and known to us on the date of this opinion letter. These opinions only relate to the laws of the British Virgin Islands which are in force on the date of this opinion letter. In giving the following opinions we have relied (without further verification) upon the completeness and accuracy, as at the date of this opinion letter, of the Registered Agent's Certificate, the Certificate of Good Standing and the Director's Certificate. We have also relied upon the following assumptions, which we have not independently verified:

2.1 Copies of documents, conformed copies or drafts of documents provided to us are true and complete copies of, or in the final forms of, the originals.

2.2 All signatures, initials and seals are genuine.

2.3 That all public records of the Company which we have examined are accurate and that the information disclosed by the searches which we conducted against the Company at the Registry of Corporate Affairs and the High Court Registry is true and complete and that such information has not since then been altered and that such searches did not fail to disclose any information which had been delivered for registration but did not appear on the public records at the date of our searches.

2.4 The Company has or will have sufficient authorised and unissued Shares under the Memorandum and Articles at the time any Shares are issued.

2.5 No invitation has been or will be made by or on behalf of the Company to the public in the British Virgin Islands to subscribe for any of the Shares.

2.6 The Company has received, or will receive, cash consideration or non-cash consideration in consideration for the issue of the Shares, and that:

(a) none of the Shares have been, or will be, issued for less than their par value; and

(b) to the extent that any Shares are, or will be, issued, in whole or in part, for non-cash consideration, the value of the non-cash consideration and cash consideration, if any, is not less than the amount credited or to be credited for such Shares.

2.7 There is nothing under any law (other than the laws of the British Virgin Islands) which would or might affect the opinions set out below. We have not made any investigation of the laws, rules or regulations of any jurisdiction other than the laws of the British Virgin Islands.

Save as aforesaid we have not been instructed to undertake and have not undertaken any further enquiry or due diligence in relation to the transaction the subject of this opinion.

3 Opinions

Based upon, and subject to, the foregoing assumptions and the qualifications set out below, and having regard to such legal considerations as we deem relevant, we are of the opinion that:

3.1 The Company is a company limited by shares incorporated with limited liability under the BVI Business Companies Act (As Revised) (the "Act"), is in good standing at the Registry of Corporate Affairs, is validly existing under the laws of the British Virgin Islands and possesses the capacity to sue and be sued in its own name.

3.2 The Shares to be offered and issued by the Company as contemplated by the Registration Statement have been duly authorised for issue, and when issued by the Company against payment in full of the consideration as set out in the Registration Statement and in accordance with the terms set out in the Registration Statement, such Shares will be validly issued, fully paid and non-assessable. As a matter of British Virgin Islands law, a share is only issued when it has been entered in the register of members.

4 Qualifications

The opinions expressed above are subject to the following qualifications:

4.1 To maintain the Company in good standing with the Registrar of Corporate Affairs under the laws of the British Virgin Islands, annual filing fees must be paid and returns made to the Registrar of Corporate Affairs within the time frame prescribed by law.

4.2 We express no view as to the commercial terms of the Registration Statement or whether such terms represent the intentions of the parties and we make no comment with respect to any representations and warranties which may be made by or with respect to the Company in any of the documents or instruments cited in this opinion or otherwise with respect to the commercial terms of the transactions the subject of this opinion.

4.3 The obligations of the Company may be subject to restrictions pursuant to United Nations and United Kingdom sanctions extended to the British Virgin Islands by Orders in Council and/or sanctions imposed by governmental or regulatory authorities or agencies in the British Virgin Islands under British Virgin Islands legislation.

4.4 Under British Virgin Islands law, the register of members is prima facie evidence of title to shares and this register would not record a third party interest in such shares. However, there are certain limited circumstances where an application may be made to a British Virgin Islands court for a determination on whether the register of members reflects the correct legal position. Further, the British Virgin Islands court has the power to order that the register of members maintained by a company should be rectified where it considers that the register of members does not reflect the correct legal position. For the purposes of the opinion given in paragraph 3.2, there are no circumstances or matters of fact known to us on the date of this opinion letter which would properly form the basis for an application for an order for rectification of the register of members of the Company, but if such an application were made in respect of the Shares, then the validity of such shares may be subject to re-examination by a British Virgin Islands court.

4.5 In this opinion letter, the phrase "non-assessable" means, with respect to the issuance of shares, that a shareholder shall not, in respect of the relevant shares and in the absence of a contractual arrangement, or an obligation pursuant to the memorandum and articles of association, to the contrary, have any obligation to make further contributions to the Company's assets (except in exceptional circumstances, such as involving fraud, the establishment of an agency relationship or an illegal or improper purpose or other circumstances in which a court may be prepared to pierce or lift the corporate veil).

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference to our firm under the heading "Validity of Securities" in the prospectus included in the Registration Statement. In providing our consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the SEC Act or the rules and regulations of the Commission thereunder.

This opinion is addressed to you and may be relied upon by you, your counsel and purchasers of

Shares pursuant to the Registration Statement. This opinion is limited to the matters detailed herein and is not to be read as an opinion with respect to any other matter.


Yours faithfully

/s/ Maples and Calder

Maples and Calder