The Smooth Fox Terrier is a breed of dog, one of many terrier breeds. It was the first breed in the fox terrier family to be given official recognition by The Kennel Club. It is well known, and although not a widely popular breed today outside hunting and show circles, it is extremely significant due to the large number of terriers believed descended from the breed.

Fox Terriers are two different breeds of the terrier dog type: the Smooth Fox Terrier and the Wire Fox Terrier. Both of these breeds originated in the 19th century from a handful of dogs who are descended from earlier varieties of British terriers, and are related to other modern white terrier breeds. In addition, a number of breeds have diverged from these two main types of fox terrier and have been recognised separately, including the Jack Russell Terrier, Miniature Fox Terrier and Rat Terrier. The Wire and Smooth Fox Terriers share similar characteristics, the main differences being in the coat and markings. They have been successful in conformation shows, more prominently in America than their homeland.