Tricia Janine Helfer (born April 11, 1974) is a Canadian actress and former model. She is best known for playing the humanoid Cylon Number Six in Ronald D. Moore's re-imagined Battlestar Galactica television series (2004–2009) and for voicing Sarah Kerrigan in the Starcraft 2 trilogy. Also played attorney Evan Smith in the American TV series Suits (2011-).

She currently stars on the Fox TV series Lucifer, having been added to the regular cast in season 2.