John Graves Simcoe, English general and politician, 1st Lieutenant Governor of Upper Canada (born 1752)

Lieutenant-General John Graves Simcoe was a British army officer, politician and colonial administrator who served as the lieutenant governor of Upper Canada from 1791 until 1796. He founded York, which is now known as Toronto, and was instrumental in introducing institutions such as courts of law, trial by jury, English common law, freehold land tenure, and also in the abolition of slavery in Upper Canada.

The following is a list of lieutenant governors of Ontario and the lieutenant governors of the former colony of Upper Canada. The office of Lieutenant Governor of Ontario was created in 1867, when the Province of Ontario was created upon Confederation. The predecessor office, lieutenant governor of Upper Canada, was a British colonial officer, appointed by the British government to administer the government of the colony, from 1791 to 1841.