Tammy Gillis is a Canadian actress. She started her acting career appearing in commercials. She later debuted in the 2000 short film The Heart of the World. She later had performances in such films as White Noise 2 and Shooter. She then had her first leading role in the independent movie Under the Apple Box. She later made notable roles on the Bravo series Girlfriend’s Guide to Divorce, as well as in the film A Novel Romance. Furthering her career on TV, she had a recurring role on Less Than Kind. After this, she appeared as Jill on Once Upon a Time. She currently plays Marissa Staub in Siren.