Beaconsfield is a suburb on the Island of Montreal, Quebec, Canada, part of the Greater Montreal region locally referred to as the West Island. I…Beaconsfield is a suburb on the Island of Montreal, Quebec, Canada, part of the Greater Montreal region locally referred to as the West Island. It is a residential community located on the north shore of Lac Saint-Louis, bordered on the west by Baie-D'Urfé, north by Kirkland and east by Pointe-Claire.