The American Pit Bull Terrier (APBT) is a dog breed recognized by the United Kennel Club (UKC) and the American Dog Breeders Association (ADBA), but not the American Kennel Club (AKC). It is a medium-sized, short-haired dog, of a solid build, whose early ancestors came from England. When compared with the English Staffordshire Bull Terrier, the American Pit Bull Terrier is larger by margins of 6–8 inches (15–20 cm) in height and 25–35 pounds (11–16 kg) in weight. The American Pit Bull Terrier varies in size: males are normally about 18–21 inches (45–53 cm) in height and around 35–60 pounds (15–27 kg) in weight, while females are normally around 17–20 inches (43–50 cm) in height and 30–50 pounds (13–22 kg) in weight.

The United Kennel Club (UKC) is a kennel club founded in 1898 in the United States. In contrast with the American Kennel Club, which is non-profit and which only clubs can join, the United Kennel Club is a profit-making corporation, open to individuals.