Happy Burstday was a studio album by the South Korean group Seventeen, released in 2025. It arrived around the group's tenth anniversary and contained sixteen songs. Alongside the title track 'Thunder', it featured contributions from all three of the thirteen-member group's sub-units (hip-hop, vocal and performance). The album mixed sturdy pop, hip-hop and ballad-like songs, with a guest turn from producer Timbaland on 'Damage'. Seventeen was known for its self-written and self-choreographed work within K-pop.