Born in Montreal, Canada, Chantal is the youngest of two children. She has one older sister named Susanne. Chantal attended College in Montreal in a Professional Theater Acting Program and has studied in acting workshops and classes around Montreal, Toronto, and New York City. Ms. Lonergan opened her own Productions Company, "Focus4 Productions" with her friend and fellow actress, Carrie Davis. Their first production, "Tremulous", in which Lonergan and Davis portrayed young suicidal girls and their journey to find their worth and life's reason, opened in New York City in August of 2001. The actresses both starred in and produced this project together.