Ock Joo-hyun (Hangul: 옥주현; sometimes spelled Ock Ju-hyun; born March 20, 1980) is a K-pop singer and musical theatre actress, known mostly for her role as the lead singer for the South Korean girl group Fin.K.L. After their unofficial breakup in 2002, Ock released three solo albums and has participated in musicals, namely Aida, Chicago, Cats, 42nd Street, and The Count of Monte Cristo.