The Staffordshire Bull Terrier is a medium-sized, stocky, and very muscular dog, with a similar appearance to the much larger American Staffordshire terrier and American pit bull terrier. It has a broad head (male considerably more so than female), defined occipital muscles, a relatively short fore-face, dark round eyes and a wide mouth with a clean scissor-like bite (the top incisors slightly overlap the bottom incisors). The ears are small. The cheek muscles are very pronounced. The lips show no looseness.

From above, the head loosely resembles a triangle. The head tapers down to a strong well-muscled neck and shoulders placed on squarely spaced forelimbs. They are tucked up in their loins and the last 1-2 ribs of the rib-cage are usually visible. The tail resembles an old fashioned pump handle. The hind quarters are well-muscled and are what give the Stafford drive when baiting. They are coloured brindle, black, red, fawn, blue, white, or any blending of these colours with white. White with any other colour broken up over the body is known as pied. Liver-coloured, black and tan dogs can occur but are rare and it is advised not to breed from either as well as those with light eyes.

The exception to the light eye rule are Blue staffies; all others should have dark brown eyes even if fawn coat. The coat is smooth and clings tightly to the body giving the dog a streamlined appearance.