Police received a call shortly before 11 p.m. ET reporting gunshots on Camille Street at Richmond Street, near Highway 20.
The two victims were discovered and transported to hospital, where the woman was pronounced dead.
A 34-year-old man was arrested by police.
The canine and major crimes units were on the scene this morning as police investigators searched for clues.
The woman’s death marks the 11th homicide in 2014 on the Montreal territory.