Dufferin—Peel—Wellington—Grey (provincial electoral district)

Dufferin—Peel—Wellington—Grey was a provincial electoral district in Ontario, Canada, that existed from 1867 to 1875. It elected two members to the Legislative Assembly of Ontario via block voting.

The riding was created with the initial formation of Ontario as a province of Canada in 1867, encompassing parts of the counties of Dufferin, Peel, Wellington, and Grey. It was abolished prior to the 1875 election, with its constituent parts redistributed into smaller, single-member ridings reflecting the growing population and settlement of the region. These ridings included, but were not limited to, Peel, Dufferin, Wellington Centre, and Grey South.

The members of provincial parliament (MPPs) who represented this district during its existence included individuals who played a role in the early development of Ontario's political landscape. Historical records detail the election results and party affiliations of those elected during the two elections held in this district. Due to the multi-member nature of the riding, voters cast two ballots, one for each of their preferred candidates.