Sealyham Terriers are medium-sized dogs, generally weighing between 24 to 40 pounds and standing approximately 10 to 12 inches tall at the shoulder. Their sturdy and compact build contributes to their versatility as a working and companion dog.

Sealyham Terriers are known for their friendly and affectionate nature. They are intelligent, alert, and can be somewhat independent. With proper training and socialization, they can be good with children and other pets, although they may exhibit a strong prey drive due to their hunting background.

They have a dense, wiry coat that protects them from the elements. The coat is typically white, though there may be some markings in colors like lemon, tan, or badger. Regular grooming is essential to prevent matting and to maintain their coat in good condition.

These terriers adapt well to various living situations, including apartments or houses with yards, provided they receive sufficient exercise. They enjoy being part of family activities and thrive in environments where they can be social and active.

Sealyham Terriers require regular exercise to stay healthy and happy. They enjoy activities such as walks, games of fetch, and agility training. Mental stimulation is also crucial; puzzle toys and obedience training can keep them engaged. Their natural hunting instincts can be harnessed in activities like trailing or working on scent trails.