The leopard (Panthera pardus) is one of the five "big cats" in the genus Panthera. It is a member of the family Felidae with a wide range in regions of sub-Saharan Africa, West Asia, the Middle East, South and Southeast Asia to Siberia. Fossil records found in Italy suggest that in the Pleistocene it ranged as far as Europe.

Compared to other members of Felidae, the leopard has relatively short legs and a long body with a large skull. It is similar in appearance to the jaguar, but is smaller and more lightly built. Its fur is marked with rosettes similar to those of the jaguar, but the leopard's rosettes are smaller and more densely packed, and do not usually have central spots as the jaguar's do. Both leopards and jaguars that are melanistic are known as black panthers.

The leopard's success in the wild is due to its well camouflaged fur; its opportunistic hunting behaviour, broad diet, and strength to move heavy carcasses into trees; its ability to adapt to various habitats ranging from rainforest to steppe and including arid and montane areas; and to run at speeds up to 58 kilometres per hour (36 mph).

A leopard pattern is a spotted color pattern, particularly in the hair coat or skin of animals, but can also describe spotting patterns in plants and fabrics. The term refers to the black and gold spotted coat of the leopard cat, but is used to describe many color combinations that result in spots scattered randomly across the skin or hair coat of other animals.

Examples of animals with coloring patterns termed leopard include many great cats in the Panthera genus, the leopard frog, the "leopard" spotting pattern in the Appaloosa and Knabstrupper breeds of horses, the leopard seal, insects such as the giant leopard moth, and fish species such as the leopard darter and the leopard shark. Examples of plants that use the term include the leopard lily, and the leopard flower.

The Lp (leopard complex) gene is responsible for the leopard color pattern in horses, which not only produces a spotted coat color but also causes mottling of the skin, a white sclera around the eye, and striped hooves. Horses with the Lp gene may be spotted all over, or may have concentrations of spots in various patterns.

The leopard in heraldry is traditionally depicted the same as a lion, but in a walking position with its head turned to full face, thus it is also known as a lion passant guardant in some texts, though leopards more naturally depicted make some appearances in modern heraldry. The Oxford Guide to Heraldry makes little mention of leopards but glosses leopard as a "term used in medieval heraldry for lion passant guardant. Now used for the natural beast." Another name for this beast is the ounce.

Early heraldic leopards

The typical heraldic leopard differs from the natural leopard (Panthera pardus) in that it has no spots and often has a mane, but is generally similar in appearance to a heraldic lion, other than its attitude. In the Middle Ages, leopards were thought to be a crossbreed between a lion and a pard,

Arthur Charles Fox-Davies wrote in 1909 that the distinction between lions (which were constantly rampant) and leopards (which were necessarily walking) originated in French heraldry and was brought into English heraldry along with so much else of English language and custom deriving from French traditions. But "the use of the term leopard in heraldry to signify a certain position for the lion never received any extensive sanction, and has long since become obsolete in British armory," though the distinction is still observed in French blazon.