In 1781, the British government purchased parts of land from the Mississauga Nation.

The assignment of laying out the townships fell to Timothy Street and Abraham Nelles. Charles Kennedy was hired by Nelles to review the northern part of the townships, and Charles Kennedy earned a significant parcel of land as payment for his work.

The brothers of Charles Kennedy, (John, Morris, Samuel and George) all attained land close to each another in the Silver Creek Valley.

A sawmill was constructed by Charles Kennedy where today Main Street meets Wildwood Road. George Kennedy also built a sawmill which became the centre of a small establishment, which was located near 10th line.

Esquesing Village (Stewarttown) was the capital of the township. In 1828, John Galt, through the Canada Company, opened the road which joined the settlement around George Kennedy's Mill with the other two settlements in the area.

As Kennedy's Mill succeeds, he built a grist mill, foundry and a woolen mill.

Around 1837, the area accepted the name Georgetown. The same year which two of the Barber Brothers (William and James) purchased the mill and land from George Kennedy.

In May 1852 a rail route through Georgetown, Brampton and Weston to Toronto was introduced.

Georgetown grew as new neighborhoods were added. The oldest section is around Main Street and Church Street, after that around King Street and Queen Street.

In the 1950s, Rex Heslop, the contractor of Rexdale in Toronto, built the Delrex subdivision. Delrex is a blend of Rex and his wife Delma's names. In the 1950s and 1960s this area was referred to as Georgetown East.

In 1989, the Georgetown South development was established and the town has grown markedly since that point.