Papillons (pah-pee-yowns) descend from the Royal Toy Spaniels of Europe. Although the breed's origins are subject to debate (Italy, Belgium, France and Spain are the leading contenders, but a few argue for Asia or Latin America), the little spaniels were well-established as continental court favorites by the Renaissance. They appear in European art as early as the 1300's, and portraits by many of the Grand Masters (e.g. Rubens, Watteau, Fragonard, and Boucher) often include a Papillon or two. Madame Pompadour and Marie Antoinette of France, Queen Sophia Dorothea of Germany, and Queen Ann of Austria are among the aristocratic ladies that allegedly owned Papillons. However, royal men also doted on these elegant little dogs: France's King Henry III is said to have carried his to court in a basket!

Papillons have not always been called Papillons. Over the years, they have been known as Epagneuls Nains, Dwarf or Continental Spaniels, Little Squirrel Dogs or Belgian Toy Spaniels. Throughout most of their history Papillons had drop ears, making their Spaniel ancestry more obvious. The erect eared Papillon now popular in the United States seems to be a mutation dating from the late 1800's. In some European countries, the name Papillon (French for "butterfly") is reserved for this erect-eared dog, while the earlier variety, the drop-eared Phalene ("night moth") is regarded as a separate breed. In the U.S. and U.K., however, the two are considered varieties of the same breed, and are shown together.

Another relatively recent change has to do with color. Early Papillons were often solid-colored. Today they are predominantly white (parti-colored) dogs with colored markings. The American Kennel Club registers Paps as white and black, white and lemon, white and red, white and sable, or tri-color (white, black and tan).