William Thompson (June 17, 1786 – January 18, 1860) was a farmer and political figure in Upper Canada.
He was born in New Brunswick in 1786, the son of a United Empire Loyalist, and came to Grantham Township with his family in 1809.
He served as captain in the local militia during the War of 1812 and fought at the Battle of Queenston Heights.
When he returned, his father had died and their property damaged; he settled in Toronto Township.
His grandson, Alfred Burke Thompson, later served in the provincial and federal parliaments.