Kim Se-Jeong (Hangul: 김세정) is a South Korean singer, dancer and actress under Jellyfish Entertainment. She debuted as a member of Gugudan in 2016. She is the Main Vocalist in Gugudan. She debuted as an actress in KBS2's drama "School 2017" as Ra Eun-Ho in 2017. She debuted in Gugudan's second sub-unit Gugudan SEMINA in 2018.