Rachelle Lefevre was born on February 1, 1979, in Montreal, Quebec, where she was raised, to an English teacher father and a psychologist mother. Her father's family is originally from France and Northern Ireland, and her maternal grandparents are Jewish. Her stepfather is a rabbi. Rachelle was raised in a non-denominational household, and identifies as Jewish. She has three sisters and speaks both English and French, though she grew up mostly speaking English. Rachelle attended Centennial Academy, a private high school, and later studied creative arts at Dawson College. She studied theater for two summers at the Walnut Hill School in Natick, Massachusetts, and began a degree in education and literature at McGill University.