At the time of the arrival of the Europeans in the 1600s, both Iroquoian and Algonquian-speaking peoples already lived in the Credit River Valley area. One of the First Nations groups the French traders found around the Credit River area were the Algonquian Mississaugas, a tribe originally from the Georgian Bay area. The name "Mississauga" comes from the Anishinaabe word Misi-zaagiing, meaning "[Those at the] Great River-mouth." By 1700 the Mississaugas had driven away the Iroquois, yet during the Beaver Wars they played a neutral or post-emptive role.
Toronto Township, consisting of most of present-day Mississauga, was formed on 2 August 1805 when officials from York (what is now the City of Toronto) purchased 84,000 acres (340 km²) of land from the Mississaugas. In January 2010, the Mississaugas and the federal government settled a land claim, in which the band of aboriginal people received $145,000,000, as just compensation for their land and lost income.
The original villages (and some later incorporated towns) settled included: Lakeview, Clarkson, Cooksville, Dixie, Erindale (called Springfield until 1890), Lorne Park, Port Credit, Sheridan and Summerville. This region would become known as Toronto Township. Part of northeast Mississauga, including the Airport lands and Malton were part of Toronto Gore Township.