While in South Korea for summer vacation in 1996, Kim stood in for a friend in a
modeling job, thus inadvertently making her entertainment debut. Despite her inexperience in show business, she left college and subsequently appeared in a Hanbul Cosmetics commercial with the slogan "I felt his scent on a strange woman," which jump-started her career. She then appeared in a
music video by Kim Hyun-cheol, and in 1997 began getting cast in supporting roles on TV but did not emerge as a star. Kim would first become well known as a film actress, debuting in the big-budget box office failure
Yesterday, but going on to play a lead role as a student teacher in the unexpected hit
Wet Dreams. Initially Kim had considered a singing career and successfully auditioned to join
Park Joon-hyung and
Park Jin-young's project mixed-gender group "GOT6" in 1997 but left the following year to pursue acting. The group then became the five-piece boy band
g.o.d. Kim's identity as an original member was only revealed by Park Joon-hyung and confirmed by Kim herself in 2015. Following her film success, Kim began to establish a niche for herself in comedies, often appearing as a straight-talking and not particularly demure comic heroine. She appeared in three films in 2003: a memorable
cameo appearance in the period comedy
Once Upon a Time in a Battlefield, opposite
Im Chang-jung in the commercially successful
The Greatest Expectation, and together with
Cha Tae-hyun in the little-watched
Happy Ero Christmas. In 2004 she took the lead role in
S Diary as a jilted woman who decides to get revenge on her ex-boyfriends. The early part of 2005 saw her star in the action-comedy ''
She's on Duty, but she would follow up by returning to the realm of TV dramas. It proved to be the best move of her career, as My Lovely Sam Soon ended up becoming the most-watched drama of 2005. The forthright, independent personality she displayed in her leading role as a woman who finds unexpected success in life as a baker endeared her to women across Korea, and later Asia, establishing her as a top star. Later that year, Kim decided to finish her college degree by transferring to Kyung Hee University as a Theater and Film major (she graduated in 2009 and received an Achievement Award from the College of Art and Design). After undergoing script revisions and a change of director and lead actress (to Yunjin Kim), Thursday's Child
was eventually renamed and released as Seven Days''. After a three-year hiatus caused by legal and contractual disputes, Kim finally got back to work in 2008, starring in the big-screen comedy
Girl Scout, and the poorly received TV drama
Night After Night (also known as ''When It's At Night''). 2009's
City Hall, where she played a low-ranking city official whose life takes a turn when she wins a pageant and later becomes the mayor, was a modest hit, with fans crediting its success to Kim's chemistry with her co-star
Cha Seung-won. Originally cast as the lead actress for 2010's
I Am Legend, Kim quit before filming started due to issues with the production (she was replaced by her good friend
Kim Jung-eun). Instead she chose the 2011
melodrama Scent of a Woman, which centers on a
spinster who, after slaving herself at a travel agency for many years, is diagnosed that she only has six months left to live, and decides to live the rest of her life happily, turning in her resignation and leaving for a vacation of luxury. She next starred in the movie
Pitch High (in Korean,
Fighting Spirit), in which she played the supportive wife of a second string baseball pitcher. In the 2012 romantic comedy series
I Do, I Do, Kim's character is a workaholic shoe designer who gets pregnant after a
one-night stand with a much younger newbie employee, then meets a charming obstetrician. She returned to the big screen in 2013
thriller The Five, based on the popular
webtoon by
Jeong Yeon-shik, in which Kim played a woman who plots revenge against the serial killer who murdered her family and left her crippled (her performance later won Best Actress at the 34th Golden Cinema Festival). In 2015, Kim was then cast in
Masked Prosecutor, about a prosecutor by day who turns into a masked vigilante by night; Kim plays the chief of a detective squad in the violent crimes unit. In October 2015, Kim signed an exclusive contract with management agency
C-JeS Entertainment. In 2017, Kim starred in the mystery thriller series
The Lady in Dignity, playing a woman from a poor family whose ambition is to become a member of the upper class. The series was a commercial and critical success, becoming JTBC's highest rated drama with a single episode rating of 12.065%. In December 2017, Kim left
C-JeS Entertainment and signed with new management agency Good People Entertainment. In 2018, Kim starred in the romance melodrama
Should We Kiss First?, playing a divorced flight attendant who finds a new love, and mystery thriller drama
Children of Nobody. In January 2025, Kim signed with the new agency Y1 Entertainment. ==Personal life==