Kim Go-eun (Korean: 김고은; born July 2, 1991) is a South Korean actress. She debuted in the film Eungyo (2012), for which she won several Best New Actress awards in South Korea. She is also known for her roles in the television series Cheese in the Trap (2016), Guardian: The Lonely and Great God (2016–2017), Yumi's Cells (2021–2022), and Little Women (2022), as well as the films Coin Locker Girl (2015), Hero (2022), and Love in the Big City.

For her performance in Exhuma (2024), Kim won several notable accolades, including the Baeksang Arts Awards and Blue Dragon Film Awards.

Kim was born in on July 2, 1991 in Seoul, South Korea. In 1994, at the age of three, she moved with her family to Beijing, China, where she lived for ten years and became fluent in Mandarin. After watching Chen Kaige's Together multiple times, Kim decided to pursue a career in filmmaking, which ultimately led her to theater. She remarked, "When I stood on the stage for the first time, I was so nervous that I thought it would be so hard if I had to do this for the rest of my life. But from my second performance, I felt ecstatic, as if I had wings on my back, and I never wanted to step off the stage. I keep on acting because I want to hold on to that feeling."

Upon returning to South Korea, she attended Kaywon High School of the Arts. After graduation, she enrolled in the School of Drama at Korea National University of Arts as part of the Department of Acting's Class of 2010. Her peers from the same cohort included Ahn Eun-jin, Lee Yoo-young, Park So-dam, Lee Sang-yi, Kim Sung-cheol, Lee Hwi-jong, and Cha Seo-won.

She made her acting debut during her college years in Jung Ji-woo's film A Muse. Kim had no prior experience in film or television, having only participated in student productions and school plays. She met director Jung Ji-woo through mutual friends and was unaware that auditions were being held. "I ended up having an audition after chatting with the director. There wasn't even any time for me to prepare," Kim recalled. Ultimately, she was selected from among approximately 300 actresses who auditioned for the role.

Director Jung said Kim grew up over the course of making the film, saying, "Her facial expressions in the last few scenes of the film are strikingly different from the ones in the beginning. I wanted to capture the moments when she realizes how precious she is to herself and to others," adding that she showed off qualities that can only be found in someone who is unaware of her own beauty and what she is capable of. He also said, "She is naturally curious and brave. She's strong in a sense that she isn't influenced easily. She doesn't do things just because everyone else does it." Kim's performance as Eun-gyo, a 17-year-old high school student who becomes the object of desire for two men, garnered her numerous Best New Actress awards that year, catapulting her from obscurity into the spotlight.

Despite many offers following A Muse, Kim took a break from acting and went back to college to complete her degree. She returned to the screen in 2014, showcasing her versatility in the thriller Monster where she played a developmentally disabled woman whose younger sister is murdered by a ruthless serial killer; her grief and rage drives her almost psychotic, and she plans her revenge.

In 2015, she and Kim Hye-soo were cast in Coin Locker Girl, a female-driven thriller based on the 1980 Japanese novel Coin Locker Babies. She was invited to the 2015 Festival de Cannes with the director and cast for this film, her first time there. Kim next starred in martial arts period drama Memories of the Sword, in which she acted opposite her longtime role model, actress Jeon Do-yeon. This was followed by courtroom film The Advocate: A Missing Body, where she played an aggressive prosecutor; and family film Canola, about a reunion between a girl and her grandmother alongside veteran actress Youn Yuh-jung.