Company: GCTS
Filing Date: 2025-03-26
Form Type: 424B3
Source: 0000929638-25-001281
Chunk: 208

Company: GCT Semiconductor Holding, Inc.
Filing Date: 2025-03-26
Form: 424B3
Chunk 208
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 compliance with the Insider Trading Policy. I further agree and represent that I will not trade in Company Securities while I am in possession of material nonpublic information regarding the Company or any of its subsidiaries.

5. This certification constitutes consent for the Company to issue any necessary stop-transfer orders to the Company’s transfer agent to enforce compliance with the Insider Trading Policy.

Signature:

Print Name:

Date:

<div align='center'>13</div>

Exhibit 23.1

<div align='center'>CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM</div>

We hereby consent to the incorporation by reference in the Registration Statements on Form S-­1 (Nos. 333-278809 and 333-279600) and Form S-8 (No. 333-280054) of GCT Semiconductor Holding, Inc. of our report dated March 25, 2025, relating to the consolidated financial statements, which appears in this Annual Report on Form 10-K.

/s/ BPM LLP

San Jose, California

March 25, 2025

Exhibit 31.1

### CERTIFICATION PURSUANT TO
<div align='center'>RULES 13a-14(a) AND 15d-14(a) UNDER THE SECURITIES EXCHANGE ACT OF 1934,

AS ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002</div>

I, John Schlaefer, certify that:

(1) I have reviewed this Annual Report on Form 10-K of GCT Semiconductor Holding, Inc.;

(2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

(3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

(4) The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and