Tricia Janine Helfer is a Canadian model and actress who is best known for her role as Cylon Number Six on Ronald D. Moore's re-imagined military science fiction series Battlestar Galactica from 2004 to 2009.

She voiced "The Grid" on the Disney XD original series Tron: Uprising and played Izzy Rogers in the CBS/ABC Studios TV show Criminal Minds and Molly Parker in the ABC TV show Killer Women.