Lee Wai Sze (Chinese: 李慧詩; Jyutping: lei5 wai6 si1; born 12 May 1987) MH, also known as Sarah Lee, is a Hong Kong professional racing cyclist. She specialises in track cycling especially as a sprinter.
Her greatest success to date is winning the bronze medal in the women's keirin at the 2012 London Olympics, Hong Kong's third-ever Olympic medal and first in cycling.
Lee was born on 12 May 1987 in Kowloon, Hong Kong. She grew up in a poor family in Ngau Tau Kok, sharing a 200-square-foot public flat with her parents and two older siblings. Lee attended two schools in the locality, Bishop Paschang Catholic School and Leung Shek Chee College.
Although born with anemia, Lee represented her school in athletics in 100 and 400 metre dash. At Form 3, her school recommended her to the Hong Kong Sports Institute and her talent was spotted by the Hong Kong Cycling Association.