Kim Yun-ja (Hangul: 김연자, Hanja: 金練子, born May 15, 1963) is a retired female badminton player from South Korea. She is the last player to win All England Open titles in both singles and doubles. In 1989, Kim married Sung Han-kook, a fellow world-class player who later went on to become the national team head coach. Sung and Kim's daughter Sung Ji-hyun is also a badminton player.