Tennant was born in Vancouver and grew up in the suburbs. In 2000, she played her first role in the romantic comedy film, Personally Yours. After that, she could be seen in some minor roles in TV series and films. In 2004, she played in the comedy horror series Kingdom Hospital. She was starring in the 2009 thriller, Zombie Punch. She won a Leo Award in the category Best Performance by a Female in a Short Drama for Valentines in 2009.Tennant played a main role in the Canadian teen sitcom Mr. Young (2011-2013).