Callum Keith Rennie is a British-born Canadian actor, based in British Columbia. His breakthrough role was as punk rocker Billy Talent in the music mockumentary Hard Core Logo (1996), followed by a starring role as Det. Stanley Raymond Kowalski on the third and fourth seasons of the television series Due South (1997–99). He then won a Genie Award for Best Actor in a Supporting Role for his performance in the Don McKellar film Last Night (1998).

Rennie's television roles include Leoben Conoy on Battlestar Galactica (2003–09), Lew Ashby on Californication (2008–13), Rick Felder on The Killing (2011–12), Gary Connell on The Man in the High Castle (2016), Karl Malus on Jessica Jones (2018), and Commander Rayner on Star Trek: Discovery (2024). He won a Gemini Award for Best Actor in a Continuing Leading Dramatic Role for his portrayal of Detective Ben Sullivan on Shattered, and a second Genie Award for the film Normal (2007). He has also won four Leo Awards.