John Cook (November 28, 1791 – November 8, 1877) was a merchant and political figure in Upper Canada and Canada West.
He was born on what was later known as Crysler's Farm in Williamsburgh Township in Upper Canada in 1791; he later sold that property to John Crysler. He served with the militia during the War of 1812 and fought at the Battle of Crysler's Farm. He represented Dundas in the Legislative Assembly of Upper Canada from 1830 to 1840 and in the Legislative Assembly of the Province of Canada from 1841 to 1845. He operated a timber business and also ran a general store in North Williamsburg. Cook was appointed justice of the peace in the Eastern District in 1835. He was sympathetic to William Lyon Mackenzie and his home was searched late one night because Mackenzie was rumoured to have paid Cook a visit.
The sons of his brother George, James William, Hermon Henry and Simon, became merchants and political figures in Ontario.