Nancy Sit Ka Yin is a Hong Kong actress on the TVB network. Her acting career dated back to the 1960s, when she was a popular teen idol alongside Connie Chan Po-chu, and Josephine Siao. Sit recorded many albums in her teens, and later served as a mentor to Anita Mui, who went on to become one of the biggest superstars in Hong Kong history.
Sit left the entertainment business after she got married and raised a family, but in the early 1990s, her marriage fell apart when her husband left her. Sit was devastated and has said she contemplated suicide. But she thought of her children, which gave her the will to continue with life. She decided to get back into show business and was able to capitalize on the popularity she had achieved as a teen idol, even though it was so many years later.
She first starred in the long-running series A Kindred Spirit, playing one of the show's central figures. It was the longest-running series in Hong Kong history, with more than 1,000 episodes.
In 1975 she joined to Flatfoot Goes East, a film of Italian director Steno with well-known actor Bud Spencer.