Dufferin County is a county and census division in Ontario, Canada. The county seat is Orangeville. The county covers 1,486.31 square kilometers (573.87 square miles) and its population in 2011 is 56,881.
Dufferin County was formed in 1881 from parts of Grey County, Simcoe County, and Wellington County, Ontario. It was named after Frederick Hamilton-Temple-Blackwood, 1st Marquess of Dufferin and Ava, who was the Governor General of Canada from 1872 to 1878.
The county has four towns:
It also has four townships: