Lee Changsub is a South Korean singer best known as a member of BTOB (비투비), the boy group that established itself as one of Cube Entertainment's flagship acts. Operating as a lead vocalist within the group, Changsub has also participated in BTOB's subunit configurations, including BTOB 4U and BTOB BLUE, extending his work across different ensemble formats within the same roster.
Group Activity & Role
Within BTOB, Changsub holds a lead vocalist position, a role he carries across the group's full lineup as well as its subunits. BTOB 4U and BTOB BLUE represent different configurations of the broader group, and Changsub's continued involvement in both reflects his central standing in the act's vocal identity. His current label affiliation is with Fantagio.
Activities Beyond Music
Changsub has maintained a presence in variety television alongside his music work. His appearances on SBS's long-running program *Running Man* have drawn public attention, including a 2026 segment that generated viewer discussion around an on-show pairing with cast member Song Ji-hyo — a storyline that drew criticism from audiences who found the framing unconvincing. The episode underscored the degree to which Changsub's public profile extends into entertainment programming outside of the recording context.
