The Ontario Derby is a Canadian Thoroughbred horse race run annually in mid-October at Woodbine Racetrack in Toronto, Ontario.

A Grade III stakes since 2012, it is open to three-year-old horses.

Raced over a distance of 1+1⁄8 miles (9 furlongs) on Tapeta, the Ontario Derby currently offers a purse of Can$150,000.

Inaugurated in 1972 as the Colonel R. S. McLaughlin Handicap, the race was renamed the Ontario Derby for the 2003 running.

Originally contested at 1+3⁄16 miles, it was changed to its current 1+1⁄8-mile distance in 1992.