Sullyoon
- Birthday: 2004-01-26
- Place of birth: Daejeon, South Korea
- Also know as: Seol Yoon-a
Seol Yoon-a (설윤아; born January 26, 2004), known professionally as Sullyoon (설윤), is a South Korean singer and MC under JYP Entertainment. She is a member of the girl group NMIXX.
