The American Bobtail is a breed of cat. It has a short "bobbed" tail about one-third to one-half the length of a normal cat's tail. This is because of a genetic mutation that affects the way their tail develops. This mutation also happens with the Manx cat.

The American Bobtail looks like the Japanese Bobtail, but they are not in the same cat breed family. The genetic mutations for their bobbed tails are different because the gene for the American Bobtail's tail is dominant and the Japanese Bobtail's is recessive.