Cobby, compact and essentially square in shape, the English Toy Spaniel is sturdy of frame and solidly constructed, with a silky, flowing coat. Its moderately rounded head, lustrous dark eyes and well-cushioned, fairly short-nosed face exemplify the important characteristics of the English Toy Spaniel. Absolute soundness and proper muscle tone is a must. Head properties should remain free of exaggeration so as to not compromise breathing and/or obstruct normal vision.

The King Charles is a friendly breed, to the extent that it is not typically as suitable as a watchdog as some breeds, though it may still bark to warn its owners of an approaching visitor. It is not a high energy breed, and enjoys the company of family members, being primarily a lapdog. Although able to bond well with children and tolerant of them, it will not accept rough handling. It prefers not to be left alone for long periods. Known as one of the quietest toy breeds, it is suitable for apartment living. The breed can tolerate other pets well, although the King Charles still has the hunting instincts of its ancestors and may not always be friendly towards smaller animals. It is intelligent enough to be used for obedience work and, due to its stable temperament, it can be a successful therapy dog for hospitals and nursing homes.