Great hornbills are fairly large, ranging from 95 to 120 cm in length and featuring a wingspan of 151 to 178 cm. On average, they weigh 3 kg. They are vividly colored and easily recognizable. The body, head, and wings are primarily black; the abdomen and neck are white. The tail is white and is crossed by a subterminal black band. A preen gland near the tail secretes tinted oil, which is spread across the feathers by the bird during grooming. This may give the bill, neck, casque, and tail and wing feathers coloration varying from yellow to red. The most recognizable feature of hornbills is the casque, which is a hollow structure located on top of the bill. It may be used by males to fight with other males and attract females. Like many other hornbills, these birds have prominent eyelashes. Males and females are similar except that the irises of males are red while those of females are white, and males have slightly larger bills and casques.
Buceros bicornis is found in mainland Southeast Asia, the Malay Peninsula and Indonesia. They are breeding residents in Bhutan, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Thailand and Vietnam. In India, they and several other hornbill species live in the Western Ghats mountain range and forests in both the northeastern and southern regions.
Great hornbills are arboreal and live mainly in wet, tall, evergreen forests. Old-growth trees that extend beyond the height of the canopy are preferred for nesting. The height of the tree and the presence of a natural cavity large enough to hold a female and her eggs are more important than the type of tree. The same nesting site is used year after year if possible. They are known to inhabit elevations of 600 to 2000 m.