Kim Sun-young made her stage debut in 1995 through After the Play Is Over. After a decade, she landed her first film appearance in the action comedy She’s on Duty. She later debuted in the small screen with a minor role in the 2014 MBC series Hotel King. Her breakthrough came in 2015 when she played a young widow with two children in the hit tvN series Answer Me 1988. In 2018, she took home several Best Supporting Actress trophies for her work in the films Communication and Lies, Happy Bus Day, and Herstory. In 2019, she joined the cast of the top-rating tvN romantic comedy Crash Landing on You, which won her Best Supporting Actress at the 56th Baeksang Arts Awards. In 2020, she bagged more Best Supporting Actress trophies for her performance in KBS2’s Oh! Samkwang Villa and MBC’s Old School Intern. In 2021, she acted alongside Moon So-ri and Jang Yoon-ju in the drama film Three Sisters, which gave her numerous acting awards including Best Supporting Actress at the 57th Baeksang Arts Awards.

Kim Sun-young is married to film director Lee Seung-won, who was at the helm of her films Communication and Lies, Happy Bus Day, and Three Sisters.