A tabby is any domestic cat that has a coat featuring distinctive stripes, dots, lines or swirling patterns, usually together with a mark resembling an M on its forehead. Tabbies are sometimes erroneously assumed to be a cat breed. In fact, the tabby pattern is found in many breeds, as well as among the general mixed-breed population. The tabby pattern is a naturally occurring feature that may be related to the coloration of the domestic cat's direct ancestor, the African Wildcat, which (along with the European Wildcat and Asiatic Wildcat) has a similar coloration.

In cat genetics, pattern is unrelated to color, and so the tabby coat pattern can show up in combination with a variety of coat colors, including tortoiseshell (tortoiseshell cats are called 'torties' whereas tortoiseshell tabby cats are often called 'torbies'). A cat's coat can be described as red tabby or gray tabby. Black and blue are colors that usually show up without tabby markings, but even among some cats of those colors a faint tabby pattern can be noticed. Bi-color cats can have the tabby pattern in the colored patches of their coat. For example, tortoiseshell cats sometimes display a pattern where the red-based and black-based tortoiseshell pattern is mixed with tabby markings. White spotting of any level can also appear in combination with tabby patterns; however, white is the only coat color that does not have any tabby markings.