Colin Cunningham (born December 29, 1986) known professionally as Colin "Doc" Brittain, is an American songwriter, producer, and musician signed to Warner Chappell Music. In 2023, he joined Linkin Park as the band's drummer.
Prior to joining Linkin Park, he wrote and produced for acts such as Papa Roach, Story of the Year, 311, A Day to Remember, Foundry, Dashboard Confessional, 5 Seconds of Summer, From Ashes to New, and One Ok Rock.
Brittain began his career playing drums in the band Oh No Fiasco, starting in 2011. Oh No Fiasco was signed to Five Seven Music where they released their debut EP, No One's Gotta Know in 2013. In the same year they were supposed to be releasing a thirteen-track album, but it was never released. The band broke up the same year, playing their last show on March 10, 2013. Afterwards, Brittain continued to work as a producer.
After working with Mike Shinoda on projects with other artists, in 2023, he joined American rock band Linkin Park as their drummer. He succeeded original drummer Rob Bourdon, who had declined to participate in the band's developing reunion. Brittain was one of two new members alongside vocalist Emily Armstrong in the band's new lineup revealed to the public on September 5, 2024.
Brittain drummed on Linkin Park's comeback album From Zero, which he co-wrote and co-produced, and the From Zero World Tour (2024 through 2026).