The snow leopard is distributed from the west of Lake Baikal through southern Siberia, in the Kunlun Mountains, in the Russian Altai mountains, Sayan and Tannu-Ola Mountains, in the Tian Shan, across Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan to the Hindu Kush in eastern Afghanistan, Karakoram in northern Pakistan, in the Pamir Mountains, and in the high altitudes of the Himalayas in India, Nepal, and Bhutan, and the Tibetan Plateau. In Mongolia, it is found in the Mongolian and Gobi Altai Mountains and the Khangai Mountains. In Tibet, it is found up to the Altyn-Tagh in the north.

Potential snow leopard habitat in the Indian Himalayas is estimated at less than 90,000 km2 (35,000 sq mi) in the states of Jammu and Kashmir, Uttarakhand, Himachal Pradesh, Sikkim, and Arunachal Pradesh, of which about 34,000 km2 (13,000 sq mi) is considered good habitat, and 14.4% is protected. In the beginning of the 1990s, the Indian snow leopard population was estimated at roughly 200–600 individuals living across about 25 protected areas.

In summer, snow leopards usually live above the tree line on mountainous meadows and in rocky regions at altitudes from 2,700 to 6,000 m (8,900 to 19,700 ft). In winter, they come down into the forests to altitudes around 1,200 to 2,000 m (3,900 to 6,600 ft). Snow leopards prefer rocky, broken terrain, and can travel without difficulty in snow up to 85 cm (33 in) deep, although they prefer to use existing trails made by other animals.

The snow leopard is a carnivore and actively hunts its prey. It is an opportunistic hunter and also eats carrion. Its preferred wild prey species are Himalayan blue sheep (Pseudois nayaur), Himalayan tahr (Hemitragus jemlahicus), argali (Ovis ammon), markhor (Capra falconeri) and wild goat (C. aegagrus).

It also preys on domestic livestock.It prefers prey ranging in weight from 36 to 76 kg (79 to 168 lb), but also hunts smaller mammals such as marmot, pika and vole species. The diet of the snow leopard varies across its range and with the time of year, and depends on prey availability.

In the Himalayas, it preys mostly on Himalayan blue sheep and Siberian ibex (Capra sibirica). In the Karakoram, Tian Shan, Altai and Mongolia's Tost Mountains, its main prey consists of Siberian ibex, Thorold's deer (Cervus albirostris), Siberian roe deer (Capreolus pygargus) and argali. Other species hunted when available include red panda, wild boar, langur monkey, snow cock and chukar partridge.

Snow leopards prefer to ambush prey from above, using broken terrain to conceal their approach. They will actively pursue prey down steep mountainsides, using the momentum of their initial leap to chase animals for up to 300 m (980 ft). They kill with a bite to the neck, and may drag the prey to a safe location before feeding. They consume all edible parts of the carcass, and can survive on a single Himalayan blue sheep for two weeks before hunting again. Annual prey needs appears to be 20–30 adult blue sheep.

The snow leopard's vocalizations include meowing, grunting, prusten, and moaning. It can purr when exhaling. It cannot roar, despite possessing partial ossification of the hyoid bone. This partial ossification was previously thought to be essential for allowing the Panthera cats to roar, but new studies show that the ability to roar is due to other morphological features, especially of the larynx, which are absent in the snow leopard.

Snow leopards are solitary animals, but share a common space. They are active mostly at dawn until early morning and again in afternoons and early evenings. They mostly rest near cliffs and ridges that provide vantage points and shade. In Nepal's Shey-Phoksundo National Park, the home ranges of five adult radio-collared snow leopards overlapped to a large extent, though they rarely met. Their individual home ranges ranged in size from 12 to 39 km2 (4.6 to 15.1 sq mi). Males moved between 0.5 and 5.45 km (0.31 and 3.39 mi) per day, and females between 0.2 and 2.25 km (0.12 and 1.40 mi), measured in straight lines between survey points, but they often zigzagged in the precipitous terrain. However, they also covered up to 7 km (4.3 mi) in a single night.

Like other cats, snow leopards use scent marks to indicate their territories and common travel routes. These are most commonly produced by scraping the ground with the hind feet before depositing urine or scat, but they also spray urine onto sheltered patches of rock. Females with her cubs usually stay together, and they rear them in dens in the mountains for extended periods.

Snow leopards become sexually mature at two to three years, and normally live for 15–18 years in the wild. In captivity they can live for up to 25 years. Oestrus typically lasts from five to eight days, and males tend not to seek out another partner after mating, probably because the short mating season does not allow sufficient time. Paired snow leopards mate in the usual felid posture, from 12 to 36 times a day. They are unusual among large cats in that they have a well-defined birth peak. They usually mate in late winter, marked by a noticeable increase in marking and calling. Females have a gestation period of 90–100 days, so the cubs are born between April and June.

The mother gives birth in a rocky den or crevice lined with fur shed from her underside. Litter sizes vary from one to five cubs, but the average is 2.2. The cubs are blind and helpless at birth, although already with a thick coat of fur, and weigh from 320 to 567 g (11.3 to 20.0 oz). Their eyes open at around seven days, and the cubs can walk at five weeks and are fully weaned by 10 weeks. Also when they are born, they have full black spots which turn into rosettes as they grow to adolescence.

The cubs leave the den when they are around two to four months of age, but remain with their mother until they become independent after around 18–22 months. Once independent, they disperse over considerable distances, even crossing wide expanses of flat terrain to seek out new hunting grounds. This likely helps reduce the inbreeding that would otherwise be common in their relatively isolated environments.

Numerous agencies are working to conserve the snow leopard and its threatened mountain ecosystems. These include the Snow Leopard Trust, the Snow Leopard Conservancy, the Snow Leopard Network, the Cat Specialist Group, TRAFFIC, and the Panthera Corporation.

In 2013, government leaders and officials from all 12 countries encompassing the snow leopard's range (Afghanistan, Bhutan, China, India, Kazakhstan, Kyrgyz Republic, Mongolia, Nepal, Pakistan, Russia, Tajikistan, and Uzbekistan) came together at the Global Snow Leopard Forum (GSLF) initiated by the President Almazbek Atambayev of the Kyrgyz Republic, and the State Agency on Environmental Protection and Forestry under the government of the Kyrgyz Republic. The meeting was held in Bishkek, the capital of the Kyrgyz Republic, and all countries agreed that the snow leopard and the high mountain habitat it lives in need trans-boundary support to ensure a viable future for snow leopard populations, as well as to safeguard their fragile environment. The event brought together many partners, including NGOs like the Snow Leopard Conservancy, the Snow Leopard Trust, and the Nature and Biodiversity Conservation Union. Also supporting the initiative were the Snow Leopard Network, the World Bank's Global Tiger Initiative, the United Nations Development Programme, the World Wild Fund for Nature, the United States Agency for International Development, and Global Environment Facility.

At the GSLF meeting, the 12 range countries signed the Bishkek Declaration to "acknowledge that the snow leopard is an irreplaceable symbol of our nations' natural and cultural heritage and an indicator of the health and sustainability of mountain ecosystems; and we recognize that mountain ecosystems inhabited by snow leopards provide essential ecosystem services, including storing and releasing water from the origins of river systems benefitting one-third of the world’s human population; sustaining the pastoral and agricultural livelihoods of local communities which depend on biodiversity for food, fuel, fodder, and medicine; and offering inspiration, recreation, and economic opportunities.