Liu Xin, also known by her stage name as Cya Liu Ya-se (simplified Chinese: 刘雅瑟; traditional Chinese: 劉雅瑟; born 13 January 1989), is a Chinese actress and singer. Formerly as a member of the Chinese girl group OP, she was noticed by the audience through her role as Zhu Xiaobei in the movie So Young (2013). In 2022, she won Best Actress at the 40th Hong Kong Film Awards for her role Wong To in Limbo.