Kim Hye-sun began modeling when she was in middle school. While attending Anyang High School of the Arts, Kim appeared in commercials for Orion, Lotte Samkang and Korea Cosmetics, and subsequently made her acting debut in 1986. She quickly gained popularity as a teen star with an innocent and bright image. Kim also became active in Japanese entertainment in 1988, where she was known under the name Shirakawa Shoko (白川翔子?) and released two photo books titled Temptation of the White Wind and Like It!. In 1993, she won Best Supporting Actress at the Blue Dragon Film Awards for her performance in Love Is Oh Yeah!.

After getting married in 1995, Kim retired from show business and immigrated to the United States. But she returned to acting two years later in the television drama The River of Maternal Love (1997). As she grew older, she began playing ajummas (middle-aged wives and mothers), notably in Famous Princesses (2006), First Wives’ Club (2007), and What’s for Dinner? (2009). Then in 2011, Kim was cast in her first big-screen leading role in 17 years. In My Secret Partner, she played a famous chef in her 40s who becomes involved in a passionate romance with a younger man in his 20s, and the film became controversial due to its explicit content, which featured Kim in a number of nude scenes.