Seo Chang-bin (born August 11, 1999), known professionally as Changbin, is a South Korean rapper, singer-songwriter and producer under JYP Entertainment. He is a member of the South Korean boy group Stray Kids and part of the hip-hop unit 3RACHA.

On May 17, 2020, he released the self composed song "Streetlight" featuring Bang Chan as part of the SKZ-PLAYER series. On December 21, 2022, Changbin participated in writing and composing his original solo song "DOODLE" for the compilation album SKZ-REPLAY. On September 1, 2023, he released the song "Fly High" composed and sang by himself, as part of a campaign for the Samsung Galaxy Z Flip 5.