Kim Hye-soo made her acting debut in the 1986 film Ggambo, which won her Best New Actress at the 23rd Baeksang Arts Awards. Her early notable works include the movies First Love and Dr. Bong, which gave her the Best Actress honors at the 1993 and the 1995 Blue Dragon Film Awards, respectively. She also took home the Daesang at the 1996 MBC Drama Awards for her work in the long-running comical series Partner. In 2003, she received another Daesang at the KBS Drama Awards for her portrayal of the titular character in the sageuk Jang Hee-bin. In 2004, she appeared in the psychological thriller film Hypnotized, which earned her several Best Actress trophies including one from the 41st Baeksang Arts Awards. In 2006, she starred in the hit crime thriller film Tazza: The High Rollers, which scored her another set of Best Actress awards. In 2013, she received her second Daesang from the KBS Drama Awards for her leading role in God of the Workplace. In 2015, she headlined the noir film Coin Locker Girl, which was screened as part of the International Critics’ Week at the 68th Cannes Film Festival. In 2016, she was named Best Actress at the 52nd Baeksang Arts Awards for tvN’s Signal.

In 2013, Kim Hye-soo admitted to and apologized for plagiarizing a substantial part of her graduate school dissertation at Sungkyunkwan University in 2001. She also expressed her willingness to forfeit her master’s degree. Kim Hye-soo’s younger brothers Kim Dong-hyun and Kim Dong-hee also pursued acting. The actress previously dated actor Yoo Hae-jin, whom she first met on the set of the 2001 film Kick the Moon.