• Birthplace: Mangyeong-eup, Gimje, South Korea
• Age: 28
• Height: 164
• Weight: 0
• Website: N/A

Kim Se-jeong, better known by the mononym Sejeong (세정), is a South Korean singer and actress signed under Jellyfish Entertainment. She is best known as the runner-up contestant in Produce 101, a former member of the girl group I.O.I, and as a member of Gugudan and its subgroup Gugudan Semina. She was a co-host of the variety show Talents for Sale in 2016 and played the leading role in the teen drama, School 2017.