Cast: Kelly Overton as Vanessa, Jonathan Scarfe as Axel, Tricia Helfer as The Dark One, Jennifer Ceon Garcia as Ivory, Aleks Paunovic as Julius, Keeya King as Violet, Nicole Munz as Jack, Neal McDonough, Vincent Gale, Rukiya Bernard, Richard Harmon and WWE star Big Show.
Tricia Helfer joined the cast in season 4 as Dracula. And Christopher Heyerdahl exited with the death of his character.
Missy Peregrym joined Van Helsing for seasons 2 and 3 as Scarlett Harker.
I saw a bit of Van Helsing filming in season one when it was based in Downtown Vancouver in the Canada Post building.
Source: The Hollywood Reporter.