In anatomy, heterochromia refers to a difference in coloration, usually of the iris but also of hair or skin. Heterochromia is primarily the result of the relative excess or lack of melanin (a pigment). However, it may also be inherited, or caused by genetic mosaicism, disease, or injury.

Below you will find a gallery of animals (mainly cats and dogs) with two different colored eyes. These are all examples of heterochromia and give each animal a very unique and memorable look.