Moon Sua
- Birthday: 1999-09-09
- Place of birth: Cheongju, South Korea
- Also know as: Moon Su Ah
Moon Su-ah is a South Korean rapper and singer managed by MYSTIC Story. She is a member of the girl group Billlie. She is best known for being a former YG Entertainment trainee and a contestant on the competition show Unpretty Rapstar 2.
