Sejeong (세정) is a South Korean singer under Jellyfish Entertainment. She is a member of the girl group gu9udan and former member of I.O.I.

In 2012, Sejeong participated in the second season of competition television show K-Pop Star 2, at the age of 17, but was eliminated from the competition. In 2016, she placed herself a spot in the group I.O.I after finishing second in Mnet's survival show Produce 101.


Digital singles



  • She represents the number 3 within her group, gu9udan.
  • During the course of Produce 101, she got the nickname "God Sejong" because she remained in first and second places and never going lower than that.
  • She trained for 1 year and 7 months until December 2015 when she participated in Produce 101. If including Produce 101, it would been 1 years and 11 months.
  • She received the nickname "Uncle Sejong" due to her actions may be perceived as manly.