Bob Larson is a radio and television evangelist, currently based in Scottsdale, Arizona. Larson has authored numerous books on the subjects of rock music, cults, and Satanism, written from a Christian perspective. He has an active following in the Usenet community at alt.fan.bob-larson.

Larson plays guitar; he has claimed his early experiences as a musician led to his concerns about occult and destructive influences in rock music. He would later incorporate his guitar playing into some of his sermons. In the 1960s, the focus of Larson's preaching centered mainly on the leftist political ideology, sexually suggestive lyrics, Eastern religious mysticism, and antisocial behavior of many of the era's rock musicians. Less flamboyant than the Peters Brothers and less sensational than Jack Chick, Jeff Godwin, or Jacob Aranza, Larson is still remembered as one of the most vocal fundamentalist Christian critics of rock music.