The Dominion Day Stakes is a Canadian Thoroughbred horse race run annually in July at Woodbine Racetrack in Toronto, Ontario. A Grade III event offering a purse of $200,000, it is open to horses aged three years and up. The race was run at a distance of 1-1/8 miles from its inception until 1983 when it was changed to its present -1/4 miles format. It was raced on dirt until 2007 when the track's new polytrack surface was installed.

Inaugurated in 1953 at the Old Woodbine Racetrack, it remained there until the track closed in 1955. The race celebrates Dominion Day, the birth of the Canadian Confederation on July 1, 1867.

Ace Marine, one of Canada's greatest runners, and its 1955 Horse of the Year, won this race in 1956. In 1972, Canada's 1973 Horse of the Year, Kennedy Road, took the Dominion. The Canadian Champion Three-Year-Old colt of 1972, Nice Dancer, won it in 1973. The 1980 Canadian Horse of the Year as well as the 1980 Champion Older Female in Canada & the USA, plus the 1981 Champion Older Female in Canada, Glorious Song, won it twice-in 1980 & 1981. In 1984, the 1984 Canadian Champion Three-Year-Old colt, Key to the Moon, won the Dominion, and in 1990, Charlie Barley (by the U.S. Triple Crown winner Affirmed) who was the 1989 Champion Grass horse in Canada, came home the winner. 1996 Canadian Horse of the Year, Mt. Sassafras has also won the Dominion Day Stakes twice: 1996 & 1999.

Among other past winners, the 1963 and 2006 editions of the Dominion Day Stakes were won by Kentucky Derby winners, Decidedly (1962) and Funny Cide (2003).