The Smooth Fox Terrier is square-proportioned, standing over a lot of ground but with a short back. Its conformation combines speed, endurance and power, enabling it to gallop and stay with the horses and hounds during the hunt and to follow a fox up a narrow passage. The gait while trotting gets most of its propulsion from the rear quarters. The expression, like the attitude, is keen; the carriage is alert and expectant. The coat is flat, hard and dense, also with a short, fine undercoat.

The Smooth Fox Terrier is friendly, alert, active, and lively without being high-strung. Through his keen expression and alert bearing, ears up and tail quivering, the Smooth Fox Terrier gives the impression of a dog ready to go anywhere and take on any task. The Smooth Fox Terrier is bold but not aggressive with people. They are affectionate with children but may be too active for some. Although seldom used for hunting now, the Smooth Fox Terrier retains a strong prey drive and will dig tirelessly after any underground vermin.