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.
It consisted of the Township of Toronto in the County of Peel, and the part of Metropolitan Toronto lying west of the Etobicoke River.
The electoral district's name was changed in late 1973 to Mississauga, on a request to by then MP Don Blenkarn, to coincide with the creation of the City of Mississauga. It was abolished in 1976 when it was redistributed between Brampton—Halton Hills, Mississauga North and Mississauga South ridings.