Annie Liu Sum-yau (Chinese: 劉心悠; born 1 April 1981) is a Hong Kong–based Taiwanese actress.

Liu was born in Taiwan but was sent to Vancouver, Canada to study at a young age by her parents.

Before starting her acting career in 2005, Liu studied industrial design at Vancouver's Emily Carr University of Art and Design.

Liu debuted as the female lead in the 2005 star-studded film, Mob Sister, and earned a Best New Performer nomination at the 25th Hong Kong Film Awards for her performance.

Pairs up with Edwin Siu TVB drama, main role