Kim's interests in music, film, and other entertainment led her to participate in a Korea-China
modeling competition in 2005, which she won top prize in. Kim was the first winner of the award who had never worked as a model. Producer Oh Se-kang saw Kim on a morning talk show, which led to her acting debut in the television series
Queen of the Game (2006). Kim plays Park Joo-won, a friend of Lee Shin-jeon (
Joo Jin-mo) and a law firm's international lawyer who loves him. Kim went on to appear in supporting roles in medical drama
Brain (2011) and spy comedy
7th Grade Civil Servant (2013), as well as a leading role in the sitcom
Standby (2012). Kim gained international attention for her roles in
Marco Polo (2014) and
Avengers: Age of Ultron (2015). signing ceremony between Korea Film Commission and
Marvel Studios (2014) '' Kim portrays
Nagini in the 2018 film
Fantastic Beasts: The Crimes of Grindelwald. In 2019, Italian fashion house
Max Mara invited her to attend the annual "Women in Film Gala", which has advocated for women and gender equality in the entertainment industry since 1973. Hence, she became the first Korean actress to the attend that event. In March 2021, Kim signed with new agency
YG Entertainment. In 2023, Kim appeared in the 1945 historical drama
Gyeongseong Creature, which aired on Netflix. In May 2025, Kim signed with new agency
Saram Entertainment. In September she hosted the closing ceremony of
30th Busan International Film Festival. ==Personal life==