Born in Vancouver, British Columbia, on August 21, 1967, Moss decided that she wanted to be an actress at an early age. The youngest of two children raised by a single mother, she grew up taking acting classes, and at the age of 20, she left Canada to pursue a career as a model. During a modeling stint in Spain, Moss managed to land a role on the TV serial Dark Justice. Upon her return to North America, she moved to L.A. and was cast on the Aaron Spelling series Models Inc.

After making her film debut in 1996's Sabotage, Moss continued to do TV work (most notably on the Toronto-based F/X: The Series) and appeared in fairly obscure films. Thanks to her starring role in The Matrix in 1999, Moss was soon in great demand. In 2000 alone, she could be seen in no less than four films, including the action comedy The Crew, Red Planet, and as a bartender with questionable motives in director Christopher Nolan's unconventional breakthrough, Memento. Subsequently taking another stab at sci-fi opposite Val Kilmer in Red Planet, Moss would next appear in Lasse Hallstrom's romantic drama Chocolat before stepping back into her vinyl bodysuit for The Matrix Reloaded and The Matrix Revolutions (both 2003).