The Greater Adjutant, Leptoptilos dubius is a large wading bird in the stork family Ciconiidae. It formerly bred in southern Asia from Pakistan and India, Sri Lanka east to Borneo, but is now restricted to two separate small breeding populations; in Assam and Cambodia. In winter, this species migrates south to Vietnam, Thailand and Burma.

The Greater Adjutant is a huge bird, typically 145-150 cm (57-60 in) tall with a 250 cm (99 in) wingspan. There are no records of the weight of wild birds, but they may be the heaviest species of stork. Its upper body and wings are black, but the belly and undertail are off-white or pale grey. The pink head and neck are bare like those of a vulture. The yellow bill is long and thick. Juveniles are a duller version of the adult.

Most storks fly with neck outstretched, but the three Leptoptilos species retract their neck in flight like a heron.

The Greater Adjutant breeds in tropical wetlands. It builds a stick nest in trees and lays between two to four eggs which are incubated by both parents for 28-30 days to hatching. It often forms small colonies.

The Greater Adjutant, like most of its relatives, feeds mainly on frogs and large insects, but also young birds, lizards and rodents. It will also eat carrion, for which its bare head and neck is an adaptation, and will feed in human refuse dumps.

Loss of nesting habitat and feeding sites through drainage, pollutions and disturbance, together with hunting and egg collection has caused a massive decline in the population of this species. The current population is estimated at less than 1,000 individuals. The Greater Adjutant is evaluated as Endangered on the IUCN Red List of Threatened Species.