The Constellation Awards are Canada's science fiction awards for excellence in film and television and they began in 2007.
David won for Best Best Male Performance in a 2006 Science Fiction Television Episode for Girl in the Fireplace, Best Male Performance in a 2007 Science Fiction Television Episode for Family of Blood, and Best Male Performance in a 2009 Science Fiction Television Episode for the Waters of Mars.
He was nominated for Best Male Performance in a 2008 Science Fiction Television Episode for Midnight, the award went to Michael Hogan from Battlestar Galactica and Best Male Performance in a 2010 Science Fiction Television Episode for The End of Time: Part II, which went to Adam Baldwin from Chuck.
Here are pictures of the awards, they change the image in the center image each year.