Cho Seong-il

Cho Seong-il (조성일), known as Seongil, is the leader, main dancer, and vocalist of Great M Entertainment's boy group 82MAJOR. Born on March 29, 2004, he carries the ESFJ warmth that earns him the group's mood maker title: the member who keeps the energy alive and the atmosphere grounded through any schedule pressure.

Seongil debuted on October 11, 2023, with 82MAJOR's first single album On, featuring lead track Sure Thing and b-side First Class. His member reveal came on January 18, 2023, after months developing through the pre-debut trainee unit Rare House under Great M Entertainment. Standing 184cm tall, his clean stage lines and precise footwork anchor the group's most demanding choreography sets.

The group name 82MAJOR pairs South Korea's international dialing code (82) with the word MAJOR, a statement of intent: first division, globally. Their fandom is 82DE, a portmanteau built on the concept of sincerity and attitude. In April 2024, 82MAJOR dropped their first mini album Beat by 82, led by the sharp, emotionally direct single Choke (촉). The October 2024 follow-up X-82 pushed further into hard-hitting territory. As leader, Seongil sets the tone in rehearsal and defines what the group projects on stage.