Justin Tranter

Justin Drew Tranter is an American songwriter, singer, and activist. They co-founded the New York City-based rock band Semi Precious Weapons, of which they were the lead singer, in 2004. The band released three studio albums before disbanding in 2014. Since the breakup of Semi Precious Weapons, Tranter has focused on songwriting, establishing a close writing partnership with Julia Michaels and working primarily with pop singers. Tranter's highest-certified songs include tracks for Justin Bieber, Selena Gomez, DNCE, Halsey, Imagine Dragons, Maroon 5, Bebe Rexha, Gwen Stefani, and Hailee Steinfeld. As of October 2025, songs written by Tranter have garnered over 70 billion streams; their single sales were estimated at 50 million as of May 2021.