The lion (Panthera leo) is a large felid of the genus Panthera native to Africa and India. It has a muscular, deep-chested body, short, rounded head, round ears, and a hairy tuft at the end of its tail. It is sexually dimorphic; adult male lions are larger than females and have a prominent mane. It is a social species, forming groups called prides. A lion's pride consists of a few adult males, related females, and cubs. Groups of female lions usually hunt together, preying mostly on large ungulates. The lion is an apex and keystone predator; although some lions scavenge when opportunities occur and have been known to hunt humans, the species typically does not.

The word 'lion' is derived from Latin: leo and Ancient Greek: λέων (leon). The word lavi (Hebrew: לָבִיא‎) may also be related. The generic name Panthera is traceable to the classical Latin word 'panthēra' and the ancient Greek word πάνθηρ 'panther'. Panthera is phonetically similar to the Sanskrit word पाण्डर pând-ara meaning 'pale yellow, whitish, white'.