Choy will officially begin her role on 26 August.
She will be responsible for overseeing the company's operations and building new business.
Doremus CEO Carl Anderson said Choy's strong background in financial services and technology plays well to Doremus' strengths in serving these important sectors.
"With her at the helm, Doremus Hong Kong is perfectly poised to help its clients succeed in this challenging market environment," he added.
Choy will report directly to Anderson and Richard Beccle, group managing director Asia Pacific for Doremus.
She was formerly marketing director for Jardine Restaurant Group overseeing the Pizza Hut brand.
Before that, Choy was general manager for JWT and also worked as Asia Pacific director of client services at FCB on the Nortel Networks and Motorola accounts.
