David Ian Hewlett (born 18 April 1968) is a British-born Canadian actor, writer, director, and voice actor known for his role as Dr. Rodney McKay on the Canadian-American science fiction TV shows Stargate SG-1, Stargate Atlantis and Stargate Universe. He is also known for his two 1993 guest appearances on Shining Time Station, portraying nosy journalist Ted Typo.

Hewlett first gained fame for his roles as Grant Jansky in the Canadian TV series Traders (1996"2000) and as David Worth in the Canadian psychological horror film Cube (1997). He had earlier appeared in the horror film Pin (1988) and the science-fiction film Scanners II: The New Order (1991). More recently, Hewlett had a prominent supporting role in Rise of the Planet of the Apes (2011), portraying bad-tempered airplane pilot Douglas Hunsiker opposite John Lithgow and Andy Serkis.