Clifton Ko (Chinese: 高志森; pinyin: Gāo Zhìsēn; born 1958) is a Hong Kong film director, actor, producer and scriptwriter. He graduated from Kwun Tong Maryknoll College, and entered TV and film industry in late 1970s, firstly worked with director Clifford Choi. In this period he wrote Choi's No U-Turn (1981) and Teenage Dreamers (Chinese: 檸檬可樂; pinyin: Ningmeng Kele; Jyutping: Ling mung hoh lok; literally: "Lemon Cola"), and John Woo's comedy Once a Thief.