A graded stakes race is a thoroughbred horse race in the United States that meets the criteria of the American Graded Stakes Committee of the Thoroughbred Owners and Breeders Association (TOBA). A specific grade level (I, II, III or listed) is then assigned to the race, based on statistical analysis of the quality of the field in previous years, provided the race meets the minimum purse criteria for the grade in question. In Canada, a similar grading system is maintained by the Jockey Club of Canada. Graded stakes races are similar to Group races in Europe but the grading is more dynamic in North America.
A high grading can also be used by racetracks to promote the race in question. When determining Eclipse Award winners, racing journalists will consider the number and grade of a horse's stakes wins during the year.
In general, stakes race refers to the stake, or entry fee, owners must pay, which generally forms part of the prize money offered to the top finishers. Not all stakes races are eligible for grading. Notably, races that are restricted to horses bred in a specific state (e.g., the Tiznow Stakes for California-breds) or country (e.g., the races that make up the Canadian Triple Crown, all restricted to Canadian-breds) are excluded, regardless of the purse or quality of field. Conversely, some races that are not technically stakes races (usually invitational races where entry fees are not required by the racetrack) may be eligible for grading if they meet the quality standards.