Relient K is a Christian punk rock band formed in 1998 in Canton, Ohio, by Matt Thiessen, Matt Hoopes, and Brian Pittman during the band members' third year in high school and their time at Malone University.

The band is named after guitarist Hoopes' automobile, a Plymouth Reliant K car, with the spelling intentionally altered to avoid trademark infringement over the Reliant name. The group is associated with the contemporary Christian music culture, most notably the Christian rock and punk scene.

The group has also performed alongside secular artists. The band has reached critical success with mainstream pop-punk and alternative rock. The band's sound incorporates piano and acoustic elements. Since its formation, Relient K has numerous studio albums and two Christmas albums.

The band has received numerous awards including two Dove Awards and a Grammy Award nomination in 2004 for Best Rock Gospel Album. Relient K has found commercial success with their studio albums, three of which peaked in the top 15 of the U.

S. Billboard 200 chart: 2004's Mmhmm, which debuted at #15; 2007's Five Score and Seven Years Ago, their fifth and most successful album, which debuted at #6; and 2009's Forget and Not Slow Down, which debuted at #15.

The band is also highly successful throughout the Christian albums and contemporary Christian music charts. On July 2, 2013, the band's seventh full-length album, Collapsible Lung, was released. On July 22, 2016, the band's eighth full-length album, Air for Free, was released.