Kim began her career as a child actress, and first appeared in the animal film Hearty Paws, alongside Yoo Seung-ho in 2006
In 2013, Kim starred in the television drama The Queen’s Classroom, which won her a Best Young Actress Award at the 2013 MBC Drama Awards. Kim next appeared in Thread of Lies, a film adaptation of Kim Ryeo Ryeong’s novel, and Her performance as a victim of bully won her the Best New Actress award at the Baeksang Arts Awards.
In 2015, Kim had a lead role in the Drama City television special, Snowy Road. The two-part drama series is about the “comfort women” in Korea under Japanese rule during World War II, and was later released as a film in theaters
In 2017, Kim starred in the web drama Sweet Revenge, which earned positive reviews and had over 11 million views online. The same year, she starred in the fantasy blockbuster Along With the Gods: The Two Worlds. The film was the second highest-grossing film in South Korea, and Kim won the Best Supporting Actress award at the Blue Dragon Awards. Kim subsequently reprised her role in the sequel of the film, Along with the Gods: The Last 49 Days.
In 2018, Kim starred in the drama film Youngju, playing a lonely girl whose environment has forced her to grow up too fast. The same year, she was cast in the two-episode romance drama Drunk in Good Taste.
In 2019, Kim starred alongside Jung Woo-sung in the drama film Innocent Witness. She earned positive reviews for her portrayal of a girl who suffers from a developmental disorder and was nominated for Best Actress in the 55th Baeksang Arts Award alongside Han Ji Min, Go Ah Sung, Kim Hye Soo, and Kim Hee Ae.
She also won the Best Actress for her role in Innocent Witness at the 39th Golden Cinema Film Festival.