The lion (Panthera leo) is one of four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg (550 lb) in weight, it is the second-largest living cat after the tiger. Wild lions currently exist in Sub-Saharan Africa and in Asia with a critically endangered remnant population in northwest India, having disappeared from North Africa, the Middle East, and Western Asia in historic times . Until the late Pleistocene, which was about 10,000 years ago, the lion was the most widespread large land mammal after humans. They were found in most of Africa, much of Eurasia from western Europe to India, and in the Americas from the Yukon to Peru.

Should they survive the rigors of cubhood, lionesses in a secure habitat, such as national parks, frequently reach an age of 12–14 years whereas male lions seldom live for longer than 8 years. However, there are records of lionesses living for up to 20 years in the wild. In captivity both male and female lions can live for over 20 years. They typically inhabit savanna and grassland, although they may take to bush and forest. Lions are unusually social compared to other cats. A pride of lions consists of related females and offspring and a small number of adult males. Groups of female lions typically hunt together, preying mostly on large ungulates. The lion is an apex and keystone predator, although they will scavenge if the opportunity arises. While lions do not typically hunt humans selectively, some have been known to become man-eaters and seek human prey.

The lion is a vulnerable species, having seen a possibly irreversible population decline of 30 to 50 percent over the past two decades in its African range. Database entry includes a lengthy justification of why this species is vulnerable. Lion populations are untenable outside of designated reserves and national parks. Although the cause of the decline is not fully understood, habitat loss and conflicts with humans are currently the greatest causes of concern. Lions have been kept in menageries since Roman times and have been a key species sought for exhibition in zoos the world over since the late eighteenth century. Zoos are cooperating worldwide in breeding programs for the endangered Asiatic subspecies.

The male lion is highly distinctive and is easily recognized by its mane. The lion, particularly the face of the male, is one of the most widely recognized animal symbols in human culture. Depictions have existed from the Upper Paleolithic period, with carvings and paintings from the Lascaux and Chauvet Caves, through virtually all ancient and medieval cultures where they historically occurred. It has been extensively depicted in literature, in sculptures, in paintings, on national flags, and in contemporary films and literature.

Etymology

The lion's name, similar in many Romance languages, derives from the Latin leo; cf. the Ancient Greek λέων (leon). The Hebrew word lavi (לָבִיא) may also be related, as well as the Ancient Egyptian rw. It was one of the many species originally described, as Felis leo, by Linnaeus in his eighteenth century work, Systema Naturae. The generic component of its scientific designation, Panthera leo, often is presumed to derive from Greek pan- ("all") and ther ("beast"), but this may be a folk etymology. Although it came into English through the classical languages, panthera is probably of East Asian origin, meaning "the yellowish animal," or "whitish-yellow".