Callum Keith Rennie is a Canadian actor who started his career in Canadian film and television projects, where his portrayal of Stanley Raymond Kowalski on the television series Due South was his first international success. After years acting in over 125 Canadian and international projects, he became widely known for his portrayal of Leoben Conoy on Battlestar Galactica, and following that, his role as record producer Lew Ashby on the Showtime series Californication. He currently stars as Commander Rayner in the fifth season of Star Trek: Discovery.

Due South is a Canadian crime comedy-drama television series created by Paul Haggis, and produced by Alliance Communications from its premiere on April 23, 1994, to its conclusion after four seasons on March 14, 1999. The series starred Paul Gross, David Marciano, Gordon Pinsent, Beau Starr, Catherine Bruhier, Camilla Scott, Ramona Milano, and Callum Keith Rennie. The show follows the adventures of Royal Canadian Mounted Police (RCMP) Constable Benton Fraser, who first came to Chicago on the trail of the killers of his father, and has remained, attached as liaison with the Canadian Consulate. He works alongside a detective of the Chicago Police Department to solve crimes. Both are aided at times by Fraser's deaf white wolf, Diefenbaker.