“My existence is rock n' roll.”

American songwriter, singer, and activist

Justin Tranter is an American songwriter, singer, and activist. They first came to prominence as the lead singer of the New York City rock band Semi Precious Weapons, which they co-founded in 2004. The band released three studio albums before splitting in 2014. After Semi Precious Weapons ended, Tranter turned chiefly to songwriting and built a close partnership with Julia Michaels. They have written mainly for pop artists, including Justin Bieber, DNCE, Selena Gomez, Halsey, Imagine Dragons, Maroon 5, Bebe Rexha, Gwen Stefani, and Hailee Steinfeld. Their songs have reached major commercial success, with over 70 billion streams by October 2025 and an estimated 50 million single sales by May 2021.