Justin Courtney Pierre is an American singer, songwriter, and guitarist originally from Mahtomedi, Minnesota. He is the co-founder and lead vocalist of the pop punk band Motion City Soundtrack, and is known for his interests and pursuits in film making and production of music.

Motion City Soundtrack is an American rock band formed in Minneapolis, Minnesota in 1997. The band's line-up consists of vocalist and guitarist Justin Pierre, lead guitarist Joshua Cain, keyboardist Jesse Johnson, bassist Matthew Taylor, and drummer Tony Thaxton. Over the course of their career, the group has toured heavily and released six studio albums, the majority on independent label Epitaph Records. The band's sound, usually described as pop-punk and/or emo, makes notable use of the Moog synthesizer. Pierre mainly handles the band's lyrics, which often touch on themes of anxiety, alienation, relationships, and self-destructive behavior.