JOO (주) is a South Korean singer under Woollim Entertainment. She debuted in January, 2008 with the single "Young Girl".
In January 2015, her contract with JYP Entertainment ended and three months later, in April, she signed an exclusive contract with Woollim Entertainment.
- Heartmade (2011)
- "Young Girl" (2008)
- "Cinderella's Sister OST Part.1" (2010)
- "Dream High OST Part.1" (2011)
- "History of a Salaryman OST Part.3" (2012)
- The Unit (KBS2, 2017–2018) - contestant