Supernatural is nominated for Best Science Fiction Television Series of 2007 and Outstanding Canadian Contribution to Science Fiction Film or Television in 2007.
Jared Padalecki and Jensen Ackles are both nominated for Best Male Performance in a 2007 Science Fiction Television Episode, Padalecki for the episode "Born Under A Bad Sign" and Ackles for the episode "What Is And What Should Never Be".
"What Is & What Should Never Be" (episode #2.20) is nominated for Best Overall 2007 Science Fiction Film or Television Script.
Samantha Smith, who plays 'Mary Winchester' on Supernatural, is nominated for Best Female Performance in a 2007 Science Fiction Film, TV Movie, or Mini-Series, for her role in Transformers.
The Constellation Awards are Canada's annual science fiction awards, focused on rewarding excellence in science fiction film and television. The 2008 Constellation Awards ceremony will be held at Polaris 22, taking place on the weekend of July 11-13, 2008.
To find out on whether you can vote, click here. Voting deadline is June 15th, 2008.
Source: The Constellation Awards website.
*Thanks to WBNX for the heads-up.