The American Bobtail is an uncommon breed of domestic cat which was developed in the late 1960s. It is most notable for its stubby "bobbed" tail about one-third to one-half the length of a normal cat's tail. This is the result of a cat body type genetic mutation affecting the tail development, similar to that of a Manx cat. The breed is not related to other short-tailed breeds, such as the Cymric cat, or the Japanese Bobtail or Kurilian Bobtail, despite the similar name and physical type—the breeding programs are entirely unrelated, and the genetic mutation causing the bobbed tail are known to be different, as the mutation causing the American Bobtail's short tail is dominant; comparatively, the Japanese Bobtail, for example, has a tail mutation that is recessive.

The Manx cat is a breed of domestic cat originating on the Isle of Man, with a mutation that shortens the tail. Many Manx have a small stub of a tail, but Manx cats are best known as being entirely tailless; this is the most distinguishing characteristic of the breed, along with elongated hind legs and a rounded head. Manx cats come in all coat colours and patterns, though all-white specimens are rare, and the coat range of the original stock was more limited. Long-haired variants are sometimes considered a separate breed, the Cymric.