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.

Mahtomedi is a city in Washington County, Minnesota, United States. The population was 7,676 at the 2010 census. Mahtomedi is a suburb of St. Paul and is located between St. Paul and Stillwater along the shores of White Bear Lake.