The Ontario Colleen Stakes is a Canadian Thoroughbred horse race run annually at the end of August at Woodbine Racetrack in Toronto, Ontario. Open to three-year-old fillies, it is raced on turf over a distance of one mile (8 furlongs). Inaugurated in 1979 at the Fort Erie Racetrack, the following year it was moved to the Woodbine Racetrack. It remained there through 1993 and then returned to Fort Erie for the 1994 running. Since 1995 it has been at the Woodbine facility. The race was run in two divisions from 1979-1989, 1993, 1995-1996.
| Stakes Race | Grade | Purse |
|---|---|---|
| Eclipse Stakes | III | $150,000 |
| Nassau Stakes | II | $300,000 |
| King Edward Stakes | II | $250,000 |
| Highlander Stakes | II | $200,000 |
| Singspiel Stakes | III | $150,000 |
| Queen's Plate Stakes | I | $1,000,000 |
| Dominion Day Stakes | III | $200,000 |
| Dance Smartly Stakes | II | $300,000 |
| Ontario Matron Stakes | III | $150,000 |
| Nijinsky Stakes | II | $300,000 |
| Royal North Stakes | III | $150,000 |
| Sky Classic Stakes | II | $250,000 |
| Ontario Colleen Stakes | III | $150,000 |
| Play the King Stakes | II | $200,000 |
| Seaway Stakes | III | $150,000 |
| Natalma Stakes | III | $200,000 |
| Summer Stakes | III | $250,000 |
| Canadian Stakes | II | $300,000 |
| Northern Dancer Turf Stakes | I | $500,000 |
| Woodbine Mile Stakes | I | $1,000,000 |
| Selene Stakes | III | $250,000 |
| Grey Stakes | III | $200,000 |
| Nearctic Stakes | I | $500,000 |
| E.P. Taylor Stakes | I | $1,000,000 |
| Canadian International Stakes | I | $1,500,000 |
| Autumn Stakes | II | $150,000 |
| Kennedy Road Stakes | III | $150,000 |
| Bessarabian Stakes | III | $150,000 |
| Valedictory Stakes | III | $150,000 |
