David Ian Hewlett (born April 18th, 1968) is a British-born Canadian actor, writer, director and voice actor who appears in the ER Season 8 episode, "Never Say Never" as Mr. Schudy. To international science fiction fans, Hewlett is best known for his role as Dr. Meredith Rodney McKay in the American-Canadian sci-fi series, Stargate SG-1, Stargate Atlantis and Stargate Universe.