Peter Langdon Preston (June 3, 1935 – October 14, 2016) was a Canadian politician in Ontario.
Preston was a non-commissioned officer with the Royal Canadian Engineers for a number of years.
He also worked in sales and management insurance, and founded Preston House in 1984 as a group home for boys aged twelve to eighteen.
Preston's first involvement in politics was as an Alderman on the Town Council in Grimsby, Ontario.
He served as a backbench supporter of the government of Mike Harris for the next four years.