Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Alpha and Omega Semiconductor Limited

Sunnyvale, California

We hereby consent to the incorporation by reference in the Registration Statements on Form S­3/A (No. 333-214666) and Form S­8 (No.333-166403,333-172173, 333-180126, 333-186480, 333-190935, 333-207987, and 333-228297) of Alpha and Omega Semiconductor Limited of our reports dated August 23, 2019, relating to the consolidated financial statements and financial statement schedules as of and for the year ended June 30, 2019, and the effectiveness of Alpha and Omega Semiconductor Limited’s internal control over financial reporting as of June 30, 2019, which appear in this Form10-K.

/s/ BDO USA, LLP

San Jose, California

August 23, 2019