The municipality was established in 1805, when government officials from York (now Toronto) bought 33,995 hectares (84,000 acres) of the land on which the Mississauga Indians lived. This land, which was known to Europeans as the "Mississauga Tract," was purchased from the Mississaugas for 1,000 pounds sterling. You could put 31,275 soccer fields in that area. This deal is often called “The First Purchase.”
The Mississaugas did not sell all of their land. Of the land they kept was about 1.6 kilometres (1 mile) on either side of the Credit River. The new owners called the land around this strip Toronto Township.
In 1806, Samuel Wilmot finished surveying the southern half of Toronto Township, and the area began to open for settlement. The new settlers called the land the “Home District”. The various communities settled in the Home District include: Clarkson, Cooksville, Dixie, Erindale, Port Credit, Sheridan, and Summerville.
The Mississaugas kept about 1.6 kilometres (one mile) of land on either side of the Credit River when they sold the first part of the Mississauga Tract, but they also sold this strip of land to the new government on February 28, 1820. The Mississaugas kept only a small land reserve for their own village. This deal is called the “The Second Purchase.”
Between 1820 and 1826, the Mississaugas lived in various locations throughout the region. In 1826, the Mississaugas lived on the south bank of the Credit River in a village built by the British Government. The Mississauga Golf Club was built on this site in 1896.
In 1847, the Mississaugas relocated to a reserve in the Grand River Valley near present-day Hagersville. Today, the only visible reminder of the Mississaugas' settlement is the historic plaque outside the gates of the Mississauga Golf Club.
By 1820, Timothy Street had completed the New Survey, and the northern part of Toronto Township opened to new immigrants. The settlements that were established in the New Survey include: Barbertown, Britannia, Burnhamthorpe, Derry West, Elmbank, Malton, Meadowvale Village, Mount Charles, and Streetsville.
Toronto Township was a municipality until 1967, when it became the Town of Mississauga.