Erin Mills is a planned community in the city of Mississauga, approximately 32 km (20 mi) west of downtown Toronto, Ontario, Canada. Erin Mills was conceived, planned and developed by the Cadillac Fairview Corporation on 8,000 acres (32 km2) of farmland in Mississauga. Erin Mills is an integrated residential, industrial and commercial community, with commercial uses concentrated in the centre and industrial uses on the periphery.
Based on census and political boundaries, the 2001 population was estimated at 105,000, making it the most populous, but not the most densely populated, area in Mississauga, and one of the fastest-growing. Geographically, the area is by far the largest in Mississauga, occupying much of the western section of the city. A number of managed creek courses traverse the area and eventually drain to the Credit River, and then Lake Ontario.
Aboriginal peoples were the first inhabitants of this area. Tribes included the Woodland, Iroquois and Mississauga. Along what was called the "Indian Trail" they hunted deer, bears and fox amongst tall stands of pine, oak and maple trees. They also fished in the river to the east, following the ancient course of a valley filled by glacial debris.