The Himalayan marmot (Marmota himalayana) is a marmot species that inhabits alpine grasslands throughout the Himalayas and on the Tibetan Plateau. It is IUCN Red Listed as Least Concern because of its wide range and possibly large population.

Arctomys himalayanus was the scientific name proposed by Brian Houghton Hodgson in 1841 who described marmot skins from the Himalayas. In the 19th century, several Himalayan marmot specimens were described and proposed as subspecies. Two genetically distinct subspecies are recognized today:

The Himalayan marmot is very closely related to the Tarbagan marmot (M. sibirica) and somewhat more distantly to the black-capped marmot (M. camtschatica). These three form a species group, with their next nearest relatives being the bobak species group, which includes the bobak marmot (M. bobak) itself, as well as the grey marmot (M. baibacina) and forest-steppe marmot (M. kastschenkoi). In the past, the relatively short-furred and short-tailed marmots of the Palearctic region, i.e. Himalayan, Tarbagan, grey and forest-steppe, were all regarded as subspecies of the bobak marmot.

The Himalayan marmot has a dense woolly fur that is rufous grey on the back and rufous yellowish on ears, belly and limbs. The bridge of its nose and end of tail is dark brown. It is one of the largest marmots in the world, being about the size of a large housecat; their average body weight ranges from 4 to 9.2 kg (8.8 to 20.3 lb), with weights lowest post-hibernation in spring and highest prior to it in autumn. In the autumn, average weight is reportedly more than 7 kg (15 lb) in both sexes. The total length is about 45 to 67 cm (18 to 26 in), with a tail length of 12 to 15 cm (4.7 to 5.9 in).

The Himalayan marmot occurs in the Himalayas and Tibetan Plateau at altitudes of 3,000–5,500 m (9,800–18,000 ft) in northeastern Pakistan, northern India, Nepal, Bhutan and China. In India, it can be seen in high-altitude regions of Ladakh and Kashmir. In China, it has been recorded in Xinjiang, Qinghai, Gansu, Tibet, western Sichuan and Yunnan provinces. In the west its distribution reaches that of the long-tailed marmot (M. caudata), but the two are not known to hybridise. The Himalayan marmot lives in short grass steppes or alpine habitats, typically above the tree line but below the permanent snow limit.

The Himalayan marmot lives in colonies and excavates deep burrows that colony members share during hibernation. The species hibernates from the late autumn to the early spring, on average for 7½ months. The burrows are between 2 and 10 m (6 ft 7 in – 32 ft 10 in) deep, provided that the upper soil layer is sufficiently light and deep such as fluvioglacial, deluvial and alluvial deposits. Where soil conditions are ideal on alluvial terraces, marmot colonies comprise up to 30 families, with up to 10 families living in an area of 1 km² (0.39 sq mi). The marmot eats plants growing on pastures, in particular the soft and juicy parts of grassy plant species like Carex, Agrostis, Deschampsia, Koeleria and flowering species like Euphrasia, Gentiana, Halenia, Polygonum, Primula, Ranunculus, Saussurea, Taraxacum, and Iris potaninii.

In Ladakh, Himalayan marmots interact with humans who feed them. This have led to greater lesser survival instinct behaviour among the marmots resulting in them being easily preyed upon by stray dogs, or other natural predators.

Females become sexually mature at the age of two years. After one month of gestation they give birth to litters of two to 11 young.