Joseph Cawthra (14 October 1759 – 15 February 1842) was a Canadian merchant and politician. Cawthra arrived in York, Upper Canada, (now Toronto) from Yeadon, Yorkshire, England, in 1802. He was granted a 400 acres (162 ha) tract of land in Mississauga, Ontario (which at the time was undeveloped rural property) by the Crown, provided he built a home on it within four years. The land remained in the hands of the Cawthra Family up until the 1970s, and much of it is now retained by the City of Mississauga as parkland.
Cawthra married Mary Turnpenny in 1801 and they had at least 9 children, 6 sons and three daughters, including:
- William Cawthra (1801–1880) - Toronto City Alderman 1836, merchant and philanthropist
- John Cawthra (1789–1851) - Newmarket merchant and member for Simcoe County in the Legislative Assembly of Upper Canada (1828–1830)
- twins Henry (1787-1854) and Joseph (1787-1790)
- Jonathan Cawthra (1791-1868) - Private in Captain Cameron's Company of the 3rd Regiment of York Militia during the War of 1812