In animal husbandry or animal fancy, a breed standard is a description of the characteristics of a hypothetical or ideal example of a breed.^: xix The description may include physical or morphological detail, genetic criteria, or criteria of athletic or productive performance. It may also describe faults or deficiencies that would disqualify an animal from registration or from reproduction.^: xix The hypothetical ideal example may be called a "breed type".

Breed standards are devised by breed associations or breed clubs, not by individuals, and are written to reflect the use or purpose of the species and breed of the animal. Breed standards help define the ideal animal of a breed and provide goals for breeders in improving stock. In essence a breed standard is a blueprint for an animal fit for the function it was bred - i.e. herding, tracking etc. Breed standards are not scientific documents, and may vary from association to association, and from country to country, even for the same species and breed. There is no one format for breed standards across all species, and breed standards do change and are updated over time.