Justin Keith Trosper is an American musician, songwriter, and record producer, born in Olympia, Washington. He fronted the post-hardcore band Unwound from 1991 to 2002 and again since the band's reunion in 2022. He has also been a member of bands such as Replikants, The Young Ginns, and Worst Case Scenario. Most of his work has been released through the independent record label Kill Rock Stars.