Cas Anvar is a Canadian actor known for his role in the SyFy/Amazon Prime Video science fiction television series The Expanse.

The Expanse is an American science fiction television series developed by Mark Fergus and Hawk Ostby for the Syfy network and is based on the series of novels of the same name by James S. A. Corey. Set in a future where humanity has colonized the Solar System, it follows a disparate band of protagonists — United Nations Security Council member Chrisjen Avasarala, cynical detective Josephus Miller, and ship's officer James Holden and his crew — as they unwittingly unravel and place themselves at the center of a conspiracy that threatens the system's fragile peace, while dealing with existential crises brought forth by newly discovered alien technology.