Patricia (Tricia) Helfer (born January 2, 1974), is a Canadian film and television actress and a former Victoria's Secret model.

Helfer was born in the rural community of Donalda, Alberta, Canada. She was raised on her family's grain farm. At the age of 17, while standing in line at a local movie theatre, she was "discovered" by modelling agency scout Kelly Streit. In 1992, she won Ford's Supermodel of the World Contest and was subsequently signed to the Elite modeling agency. Modelling clothes for Givenchy, Christian Dior, Claude Montana and Emanuel Ungaro, Helfer has also appeared on the covers of fashion magazines ELLE (August 1993), Amica Italia (November 1996), Cosmopolitan (July 1998), and Vogue. She has done photo assignments for Chanel's Cristalle perfume and Victoria's Secret lingerie.

Helfer hosted a television fashion program Ooh La La in Canada, before moving to New York City to learn acting. She relocated to Los Angeles in 1996 to pursue a full-time film career. Apart from starring in a number of fashion documentaries, Helfer appeared on the comedy short Eventual Wife, as Inga, in 2000. She also co-starred as Sarah on the television series Jeremiah and played the role of a model, Ashleigh James, in the May 16, 2002 episode "The Hunger Artist" on CSI: Crime Scene Investigation. In 2003, Helfer played the female lead Eva in the independent film White Rush. She also became a noted beauty pageant judge for Miss Teen USA and Miss USA.

Helfer appeared as a gynoid Cylon agent, Number Six, in the 2003 Sci Fi channel miniseries Battlestar Galactica. The miniseries, which was a remake of the 1970s series Battlestar Galactica, was a huge ratings success, due in part to the visually attractive mind games between Number Six and scientist Dr. Gaius Baltar; it has now become a television series in which Helfer is a main cast member.

Early in 2004, Helfer was offered the role depicting Farrah Fawcett in the NBC telemovie Behind the Camera: The Unauthorized Story of 'Charlie's Angels'. She also regularly appeared in photo shoots by Maxim magazine and was the magazine's wall calendar girl for 2005.

In November of 2005, Helfer was named as the host of Canada's Next Top Model, which is scheduled to debut in 2006. Tricia Helfer is known as a supermodel turned actor, because she became famous as a model.

Helfer has been married to lawyer Jonathen Marshall since 2002.