Maltese dog refers both to an ancient variety of dwarf canine from Italy and generally associated also with the island of Malta, and to a modern breed of dog in the toy group. The contemporary variety is genetically related to the Bichon, Bolognese, and Havanese breeds. The precise link, if any, between the modern and ancient species is not known. Nicholas Cutillo suggested that Maltese dogs might descend from spitz-type canines, and that the ancient variety probably was similar to the latter Pomeranian breeds with their short snout, pricked ears, and bulbous heads. These two varieties, according to Stanley Coren, were perhaps the first dogs employed as human companions.

The modern variety traditionally has a silky, pure-white coat, hanging ears and a tail that curves over its back, and weighs up to 3–4 kg (7–9 lb). The Maltese does not shed. The Maltese is kept for companionship, ornament, or competitive exhibition.