Christopher Heyerdahl (born September 18, 1963) is a Canadian actor who has had roles in many television shows and movies.
Heyerdahl is primarily known for his recurring role as "The Swede" in AMC's Hell on Wheels. He is also known for his role as Leonid in the Are You Afraid of the Dark? episode "The Thirteenth Floor" and as Nosferatu in the episode "Midnight Madness". He played the characters Halling and Wraith commander Todd in Stargate Atlantis, and Pallan in the Stargate SG-1 episode "Revisions". He played H. P. Lovecraft in the film Out of Mind: The Stories of H. P. Lovecraft (1998) and a punk, new at drug dealing, inCadavres (2009).
He played the part of the demon Alastair in three episodes of Supernatural. He also played the part of Zor-El in the television series Smallville, as well as playing John Druitt and Bigfoot in the series Sanctuary.
He had a role in the feature film New Moon, an adaptation of Stephenie Meyer's second book in her Twilight Saga. In this film, he played a vampire, Marcus, who is part of a powerful Italian family called the Volturi. He reprised that role in both parts of Breaking Dawn, the two part adaption of the fourth book in the Twilight Saga.
He played the part of Dieter Braun on True Blood during the show's 5th season, which aired summer 2012. Heyerdahl also plays the role of Thor Gundersen/"The Swede", in the AMC television series Hell on Wheels from 2011 through its concluding season (2016).