Amanda Tapping is a British-Canadian actress and director. She is best known for portraying Samantha Carter in the Canadian–American military science fiction television series Stargate SG-1, Stargate Atlantis, and Stargate Universe. She also starred as Helen Magnus in the science fiction-fantasy television series Sanctuary.

Dr. Helen Magnus is the protagonist and central character of the Canadian fantasy-science fiction television series Sanctuary. She is portrayed by Amanda Tapping. In the series, Magnus is a biologist from Victorian era England, who currently runs the global Sanctuary Network, an organization tasked with finding a series of creatures called "abnormals", and later bringing them to a Sanctuary base for refuge, to protect them from the human population. The character is over two and a half centuries old, having been given her advanced longevity by injecting herself with vampire blood, as well as reliving the 20th century from temporal displacement. After traveling back in time, Magnus had to avoid people, so she isolated herself. In the season 4 finale "Sanctuary For None: Part 2", it was revealed that Magnus spent the 113 years creating a new Sanctuary.