Jeonghan was born on October 4, 1995, as 윤정한 (Yoon Jeong Han) in Jeju, South Korea. He is a Korean singer-songwriter and a member of the South Korean boy band SEVENTEEN and its sub-unit Vocal Team. Currently, he is signed with Pledis Entertainment.

Jeonghan was scouted while he was in the subway station. He then became a trainee of Pledis Entertainment, and debuted as a member of SEVENTEEN on May 26, 2015.

He is also a songwriter of SEVENTEEN, having written many SEVENTEEN’s songs, included “Don’t Wanna Cry”, “CLAP”, and many more.