Oh Yeon-soo debuted in the entertainment industry in 1989 after passing an open audition by MBC. Her first acting credit was the 1990 MBC series The Dancing Gayageum, which won her Best New Actress at the 27th Baeksang Arts Awards. In 1992, she received the Best New Actress honors at the 3rd Chunsa Film Art Awards for the movie Man Upstairs, Woman Downstairs, in which she was paired with Choi Su-jong. Also in 1992, she appeared in the crime film General’s Son III, which scored her two more Best New Actress trophies at the 13th Blue Dragon Film Awards and the 29th Baeksang Arts Awards. In 2004, she took home a Top Excellence Award at the KBS Drama Awards for her portrayal of a divorcee who rebuilds her life and rediscovers love in A Second Proposal. In 2006, she joined the cast of the megahit MBC sageuk Jumong, which bagged the Daesang at the 43rd Baeksang Arts Awards. In 2013 and 2014, she played key roles in KBS2’s IRIS 2 and MBC’s Triangle.

Oh Yeon-soo married actor Sohn Ji-chang in 1998 after dating in secret for six years. They have two sons together.