Matthew Thiessen is a Canadian-American singer-songwriter known for being co-founder and primary songwriter for the Christian rock band Relient K. With Relient K, he has released eight full-length albums, including three that were certified Gold, and three that peaked in the top twenty on the Billboard 200. Outside of his work with Relient K, Thiessen maintains a side project called Matthew Thiessen and the Earthquakes. In 2009, he co-produced and collaborated on Owl City's album Ocean Eyes.