Oh Yoon-ah started out as a racing model and won the first Cyber Race Queen Contest in 2000. She then became an entertainment reporter for MBC’s Section TV in 2003. In 2004, she debuted as an actress in the SBS series Into the Storm. That same year, she became a household name following her portrayal of the heroine’s friend in the hit KBS2 sitcom Old Miss Diary. In 2006, she was named Best Supporting Actress at the SBS Drama Awards for her work in the romantic melodrama Alone in Love. In 2010, she was nominated for two Excellence Awards at the KBS Drama Awards for her performance in God of Study and Marry Me, Please. In 2013 and 2014, she scored back-to-back nominations for a Special Acting Award at the SBS Drama Awards for Incarnation of Money and You’re All Surrounded. In 2020, she took home the Best Entertainer Award in Reality Category at the KBS Entertainment Awards for her appearance on Stars’ Top Recipe at Fun-Staurant. Also in 2020, she became part of the KBS2 drama Once Again, which won her Best Supporting Actress at the KBS Drama Awards.

Oh Yoon-ah married an advertising executive in January 2007. They divorced in 2015. They have one son who has autism.