The Park’s fauna is much less specialised than its plant life and is more representative of Borneo as a whole. Only the Kinabalu rat, a friendly and harmless inhabitant of the summit zone is restricted to the mountain. larger animals in the park include three species of deer, breaded pig, gibbon and the honey bear. Only the elephant and rhinoceros, are missing. The orang utan is quite common within the Park, but keeps to deep forest where it searches for fruits in small family groups. Squirrels, bats, tree shrews and rats are well represented and are the animals most likely to be seen by visitors.

An estimated 300 species of birds, 2/3 of those to be found in Borneo, live in or visit the park. Many of these can be easily observed from roads and trails. Each zone of vegetation has its characteristic birds. The rare Kinabalu Warbler lives on Kinabalu and Mt. Trus Madi (64 kms to the south), and no-where else in the world. The Mountain blackbird is not found elsewhere in Borneo. The Blackbird and the Mountain Blackeye are the two most common birds of the high altitudes on Kinabalu.

At Park Headquarters, in the montane forest, visitors are likely to notice the Grey Drongo (fork-taled and insect-catching), the noisy, long-tailed Malaysian Tee-pie and the quiet hunting parties of plump Chesnut-capped Laughing Thrushes. The chattering flocks of tiny crested birds are Minlas, representative of a Himalayan genus. As with the flora, birdlife in the lowlands is much more diverse than at the higher elevation. At the Hot Springs visitors will see the black and white Magpie Rohin and hear the melodious songs of the White-rumped Shama. Many others will also be observed there and for better observation, binoculars will be useful.