| Bill Stewart | |
| Office1: | Ontario MPP |
| Term Start1: | 1957 |
| Term End1: | 1975 |
| Predecessor1: | Thomas L. Patrick |
| Successor1: | Riding abolished |
| Constituency1: | Middlesex North |
| Party: | Progressive Conservative |
| Birth Date: | 26 February 1915 |
| Birth Place: | London, Ontario |
| Death Place: | London, Ontario |
| Occupation: | Farmer |
| Portfolio: | Minister without portfolio, 1960–1961 |
| Spouse: | Edythe Jones |
| Children: | 4 |
William Atcheson Stewart (February 26, 1915 - December 8, 1990) was a politician in Ontario, Canada. He was a Progressive Conservative member of the Legislative Assembly of Ontario from 1957 to 1975 who represented the southwestern Ontario riding of Middlesex North. He served as a cabinet minister in the governments of Leslie Frost, John Robarts, and Bill Davis.
Stewart was a cattle farmer in Denfield, Ontario.[1] He married Edythe Jones and together they raised four daughters.
In 1957, Stewart was elected in a by-election in the riding of Middlesex North to replace Thomas L. Patrick who had died that year. He defeated Liberal candidate A.E. Smith by 3,134 votes.[2] He was re-elected in 1959, 1963, 1967, and 1971. In 1960, Leslie Frost appointed him to cabinet as a Minister Without Portfolio. In 1961 he was appointed by new Premier, John Robarts as Minister of Agriculture.[3] He retained the cabinet position for 15 years until his retirement in 1975.[4]
In 1983, he was appointed the fourth chancellor of the University of Guelph.[5] In 1976, he was awarded an honorary LL.D. from the University of Guelph. He was elected to the Canadian Agricultural Hall of Fame in 1988.