The Asian elephant (Elephas maximus), also known as the Asiatic elephant, is the only living species of the genus Elephas and is distributed throughout the Indian subcontinent and Southeast Asia, from India in the west, Nepal in the north, Sumatra in the south, and to Borneo in the east. Three subspecies are recognised—E. m. maximus from Sri Lanka, E. m. indicus from mainland Asia and E. m. sumatranus from the island of Sumatra.

      The Asian elephant is the largest living land animal in Asia. Since 1986, the Asian elephant has been listed as Endangered on the IUCN Red List, as the population has declined by at least 50 percent over the last three elephant generations, which is about 60–75 years. It is primarily threatened by loss of habitat, habitat degradation, fragmentation and poaching. In 2019, the wild population was estimated at 48,323-51,680 individuals. Female captive elephants have lived beyond 60 years when kept in semi-natural surroundings, such as forest camps. In zoos, Asian elephants die at a much younger age; captive populations are declining due to a low birth and high death rate.

      The genus Elephas originated in Sub-Saharan Africa during the Pliocene and spread throughout Africa before expanding into the southern half of Asia. The earliest indications of captive use of Asian elephants are engravings on seals of the Indus Valley Civilisation dated to the 3rd millennium BC.

      On average, when fully-grown, males are about 2.75 m (9.0 ft) tall at the shoulder and 4 t (4.4 short tons) in weight, while females are smaller at about 2.40 m (7.9 ft) at the shoulder and 2.7 t (3.0 short tons) in weight. Sexual dimorphism in body size is relatively less pronounced in Asian elephants than in African bush elephants; with males averaging 15% and 23% taller in the former and latter respectively. Length of body and head including trunk is 5.5–6.5 m (18–21 ft) with the tail being 1.2–1.5 m (3.9–4.9 ft) long.

      The distinctive trunk is an elongation of the nose and upper lip combined; the nostrils are at its tip, which has one finger-like process. The trunk contains as many as 60,000 muscles, which consist of longitudinal and radiating sets. The longitudinals are mostly superficial and subdivided into anterior, lateral, and posterior. The deeper muscles are best seen as numerous distinct fasciculi in a cross-section of the trunk. The trunk is a multipurpose prehensile organ and highly sensitive, innervated by the maxillary division of the trigeminal nerve and by the facial nerve. The acute sense of smell uses both the trunk and Jacobson's organ. Elephants use their trunks for breathing, watering, feeding, touching, dusting, sound production and communication, washing, pinching, grasping, defense and offence.

      The "proboscis" or trunk consists wholly of muscular and membranous tissue, and is a tapering muscular structure of nearly circular cross-section extending proximally from the attachment at the anterior nasal orifice, and ending distally in a tip or finger. The length may vary from 1.5 to 2 m (59 to 79 in) or longer depending on the species and age. Four basic muscle masses—the radial, the longitudinal and two oblique layers—and the size and attachments points of the tendon masses allow the shortening, extension, bending, and twisting movements accounting for the ability to hold, and manipulate loads of up to 300 kg (660 lb). Muscular and tendinous ability combined with nervous control allows extraordinary strength and agility movements of the trunk, such as sucking and spraying of water or dust and directed airflow blowing.

      The trunk can hold about four litres of water. Elephants will playfully wrestle with each other using their trunks, but generally use their trunks only for gesturing when fighting.

      Tusks serve to dig for water, salt, and rocks, to debark and uproot trees, as levers for maneuvering fallen trees and branches, for work, for display, for marking trees, as a weapon for offence and defense, as trunk-rests, and as protection for the trunk. Elephants are known to be right or left tusked.

      Female Asian elephants usually lack tusks; if tusks—in that case, called "tushes"—are present, they are barely visible and only seen when the mouth is open. The enamel plates of the molars are greater in number and closer together in Asian elephants. Some males may also lack tusks; these individuals are called "filsy makhnas", and are especially common among the Sri Lankan elephant population.

      Skin color is usually grey, and may be masked by soil because of dusting and wallowing. Their wrinkled skin is movable and contains many nerve centers. It is smoother than that of African elephants and may be depigmented on the trunk, ears, or neck. The epidermis and dermis of the body average 18 mm (0.71 in) thick; skin on the dorsum is 30 mm (1.2 in) thick providing protection against bites, bumps, and adverse weather. Its folds increase surface area for heat dissipation. They can tolerate cold better than excessive heat. Skin temperature varies from 24 to 32.9 °C (75.2 to 91.2 °F). Body temperature averages 35.9 °C (96.6 °F).

      Asian elephants have a very large and highly developed neocortex, a trait also shared by humans, apes and certain dolphin species. They have a greater volume of cerebral cortex available for cognitive processing than all other existing land animals. Results of studies indicate that Asian elephants have cognitive abilities for tool use and tool-making similar to great apes. They exhibit a wide variety of behaviors, including those associated with grief, learning, allomothering, mimicry, play, altruism, use of tools, compassion, cooperation, self-awareness, memory, and language. Elephants reportedly head to safer ground during natural disasters like tsunamis and earthquakes, but data from two satellite-collared Sri Lankan elephants indicate this may be untrue.

      Elephants are crepuscular. They are classified as megaherbivores and consume up to 150 kg (330 lb) of plant matter per day. They are generalist feeders, and are both grazers and browsers. They are known to feed on at least 112 different plant species, legume, palm, sedge and true grass families. They browse more in the dry season with bark constituting a major part of their diet in the cool part of that season. They drink at least once a day and are never far from a permanent source of fresh water. They need 80–200 liters of water a day and use even more for bathing. At times, they scrape the soil for clay or minerals.

      Adult females and calves move about together as groups, while adult males disperse from their mothers upon reaching adolescence. Bull elephants are solitary or form temporary "bachelor groups". Cow-calf units generally tend to be small, typically consisting of three adults (most likely related females) and their offspring. Larger groups of as many as 15 adult females have also been recorded. Seasonal aggregations of 17 individuals including calves and young adults have been observed in Sri Lanka's Uda Walawe National Park. Until recently, Asian elephants, like African elephants, were thought to be under the leadership of older adult females, or matriarchs. It is now recognized that females form extensive and very fluid social networks, with varying degrees of associations between individuals. Social ties generally tend to be weaker than in African elephants.

      Unlike African elephants, which rarely use their forefeet for anything other than digging or scraping soil, Asian elephants are more agile at using their feet in conjunction with the trunk for manipulating objects. They can sometimes be known for their violent behavior.

      Asian elephants are recorded to make three basic sounds: growls, squeaks and snorts. Growls in their basic form are used for short distance communication. During mild arousal, growls resonate in the trunk and become rumbles while for long-distance communication, they escalate into roars. Low-frequency growls are infrasonic and made in many contexts. Squeaks come in two forms; chirpings and trumpets. Chirping consists of multiple short squeaks and signal conflict and nervousness. Trumpets are lengthened squeaks with increased loudness and produced during extreme arousal. Snorts signal changes in activity and increase in loudness during mild or strong arousal. During the latter case, when an elephant bounces the tip of the trunk it creates booms which serve as threat displays.: 142 Elephants are able to distinguish low-amplitude sounds.

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