Ken began playing guitar at age six and singing at age nine. Despite being raised in a Christian home, he was not openly Christian until some time before he began his musical career. Tamplin overdosed on angel dust four times, used and sold cocaine, hash and other drugs before the age of 14, when he became a Christian again. "I've been on fire for Him ever since", Tamplin was quoted as saying.
Tamplin is one of the founding members of the group Shout, along with Chuck King. He is also the winner of four Dove awards, including Hard Music Album of the Year at the 24th GMA Dove Awards in 1993, for his album Tamplin.
In 2001 Tamplin produced the album Make Me Your Voice, featuring gospel singer Andrae Crouch, to help raise funds for Christian groups working in Sudan.