Yoon Yoo-sun started out as a child actress in 1975. Some of her early works are the films The Flying Iljimae in 1978 and Colors of the Rainbow in 1980. She also appeared in KBS1’s The Supreme Order and MBC’s Tiger Teacher, which both aired in 1981. The following year, she played the titular character in the musical Snow White. In 1989, she was named Best New Actress at the 25th Baeksang Arts Awards for her performance in the KBS1 drama Land. In 1994, she starred in the award-winning film The Story of Two Women, which won her Best New Actress at the 32nd Grand Bell Awards. In 1995, she took home an Excellence Award as well as the Popularity Award at the KBS Drama Awards for Even If the Wind Blows. In 2010, she played a supporting role in the SBS fantasy romantic comedy My Girlfriend Is a Gumiho, which gave her a Best Supporting Actress nomination at the SBS Drama Awards. In 2011, she bagged a Top Excellence Award at the MBC Entertainment Awards for the popular sitcom High Kick: Counterattack of the Short Legs. In 2018, she received an Excellence Award nomination at the MBC Drama Awards for Wealthy Son.

Yoon Yoo-sun has two children with her husband Lee Sung-ho. She is the aunt of Infinite’s Lee Sung-yeol and Golden Child’s Lee Dae-yeol.