Oh Yoon-ah began her career as a racing model (“race queen” or “pit babe”), and in 2000 she won the first Cyber Race Queen Contest.

Oh made her acting debut in 2004 TV series Into the Storm, but it was her supporting role as the heroine’s friend in hit sitcom Old Miss Diary that made her into a household name. Oh continued acting on television, starring in That Woman, Mr. Goodbye, Surgeon Bong Dal-hee, Master of Study, Marry Me, Please, and notably Alone in Love, for which she won Best Supporting Actress at the 2006 SBS Drama Awards.