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 was initially formed in 1999 by lead guitarist/vocalist Tyler Connolly and bassist Dean Back.

Starting on March 1, 2005, Theory began a promotional tour, headlined by Breaking Benjamin and The Exies.

Songs from Gasoline appeared in the soundtrack of the 2005 video game Fahrenheit, which was released under the title Indigo Prophecy in the United States.

The band performed the theme song to World Wrestling Entertainment's No Way Out 2006 pay-per-view, a cover version of "Deadly Game" from the WWE Anthology album.

Theory also performed in the 96th Grey Cup halftime show, along with Suzie McNeil and Andree Watters, on November 23, 2008.

[6] Total Nonstop Action used Theory of a Deadman's song "Got it Made", from the album Scars & Souvenirs, for their special 2008 year review video.

[8] In late 2010, it was announced that the band would start recording their fourth studio album, which was projected to be released in mid-2011.

[11][better source needed] The title of the upcoming album was announced to be The Truth Is...[12] In 2011, Theory co-headlined the second annual Carnival of Madness Tour with Alter Bridge.

The band contributed a new song, which was co-written with The Exies singer Scott Stevens, called "Head Above Water", to the Transformers: Dark of the Moon soundtrack, which was released on June 14, 2011.

Another track titled "Drag Me to Hell" was made available for free through the official Roadrunner Records website on June 16, 2011.

On July 1, 2011, the unreleased single, "Let Me Go", featuring Pop Idol's Cveta Majtanović, was also released via CloudMusic and for the parted collaboration music video.

On November 11, 2016, the band released a cover of the song "Hallelujah" by Leonard Cohen, a tribute in recognition of his death on the seventh of the same month.

They released two cover singles shortly after—Sting's "Shape of My Heart" in February and Major Lazer's "Cold Water" on March 17.

[29] In August 2019, Connolly informed the public that the group would continue their 2019 headlining tour efforts in September.