Exhibit 5.1

Our ref         SMC/670011-000002/38600021v9

Ichor Holdings, Ltd.

PO Box 309, Ugland House

Grand Cayman

KY1-1104

Cayman Islands

8 December 2016

Dear Sirs

Ichor Holdings, Ltd. (the “Company”)

We have acted as Cayman Islands counsel to the Company to provide this legal opinion in connection with the Company’s registration statement on Form S-1, including all amendments or supplements thereto, filed with the United States Securities and Exchange Commission (the “Commission”) under the United States Securities Act of 1933 (the “Act”), as amended, (File No. 333-214588) (the “Registration Statement”) in respect of the proposed initial offering (the “IPO”), and a new registration statement filed pursuant to Rule 462(b) (the “Rule 462(b) Registration Statement” and together with the Registration Statement, the “Registration Statements”) under the Act. The Rule 462(b) Registration Statement covers the public offering in connection with the IPO of an additional 146,945 ordinary shares, par value US$0.0001 per share, in the capital of the Company (the “Shares”), including up to 19,167 ordinary shares issuable upon exercise of an over-allotment option granted to the underwriters. Such public offering is being underwritten pursuant to an underwriting agreement (the “Underwriting Agreement”) among the Company and the underwriters named therein. This opinion is given in accordance with the terms of the Legal Matters section of the Registration Statements.

We have reviewed originals, copies, drafts or conformed copies of the following documents and such other documents or instruments as we deem necessary:

The following opinion is given only as to, and based on, circumstances and matters of fact existing and known to us on the date of this opinion. This opinion only relates to the laws of the Cayman Islands which are in force on the date of this opinion. In giving this opinion we have relied (without further verification) upon the completeness and accuracy of the factual confirmations contained in the Director’s Certificate and the Certificate of Good Standing. We have also relied upon the following assumptions, which we have not independently verified:

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:

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Under Cayman Islands law, the register of members (shareholders) 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 Cayman Islands court for a determination on whether the register of members reflects the correct legal position. Further, the Cayman 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. As far as we are aware, such applications are rarely made in the Cayman Islands, but if this were to occur in respect of the Company’s Shares, then the validity of such shares may be subject to re-examination by a Cayman Islands court.

Except as specifically stated herein, 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.

In this opinion, the phrase “non-assessable” means, with respect to the Shares in the Company, that a shareholder shall not, solely by virtue of its status as a shareholder, be liable for additional assessments or calls on the Shares by the Company or its creditors (except in exceptional circumstances, such as involving fraud, the establishment of an agency relationship or an illegal or improper purpose or other circumstance in which a court may be prepared to pierce or lift the corporate veil).

To maintain the Company in good standing under the laws of the Cayman Islands, annual filing fees must be paid and returns made to the Registrar of Companies within the time frame prescribed by law.

We hereby consent to the filing of this opinion as an exhibit to the Rule 462(b) Registration Statement and to the reference to our firm under the heading “Legal Matters” in the prospectus included in the Rule 462(b) 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 Act or the Rules and Regulations of the Commission thereunder.

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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

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Ichor Holdings, Ltd.

PO Box 309, Ugland House

Grand Cayman

KY1-1104

Cayman Islands

7 December 2016

Dear Sirs

Ichor Holdings, Ltd. (the “Company”)

I, being a director of the Company, am aware that you are being asked to provide a legal opinion (the “Opinion”) in relation to certain aspects of Cayman Islands law. Capitalised terms used in this certificate have the meaning given to them in the Opinion. I hereby certify, as matters of fact, that:

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I confirm that you may continue to rely on this certificate as being true and correct on the day that you issue the Opinion unless I shall have previously notified you in writing personally to the contrary.

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