Once a Cop (Chinese: 超級計劃) is a 1993 Hong Kong action film directed by Stanley Tong and starring Michelle Yeoh. It is a spin-off of Jackie Chan's Police Story film series involving the character Yeoh portrayed in Police Story 3: Super Cop.The film is also known as Project S in original territories and many other titles, including Police Story IV (inaccurately), Police Story 3 Part 2, Supercop (UK) and Supercop 2 (US).