Theory of a Deadman

Theory of a Deadman (abbreviated as Theory or T.O.A.D) is a Canadian rock band from North Delta, British Columbia. Formed in 1999, the band is currently signed to Roadrunner Records as well as 604 Records. The band's music has hints of various music styles, such as country and acoustic, in addition to their post-grunge and alternative rock foundation. Nine of their singles have entered the top ten of the US Billboard Mainstream Rock chart, including four songs that peaked at number one: "Bad Girlfriend", "Lowlife", "Rx (Medicate)", and "History of Violence".

Theory of a Deadman's music style has generally been regarded as post-grunge, hard rock, alternative rock, and pop rock. The band also mixes country, pop, and acoustic elements into their sound.