Calico sheep is a type of sheep that has more than one colour within its coat.^[1] The colouring is due to a piebald mutation, but the calico sheep is not a recognized breed.

These sheep tend to be very small due to intensive inbreeding and are often mislabeled as a true breed. Rather, they are mere crossbred sheep that have interesting colour patterns.

The calico mutation is due to an autosomal recessive gene, first reported by Roberts.^[1]

Calico sheep are not related to the black and white sheep that are native to ancient Sudan^[2] and to South Africa.^[3]

The modern mutation was developed by breeding Shetland sheep with Barbados Blackbelly Sheep.^{[citation needed]}

• Calico cat