The white-bellied drongo (Dicrurus caerulescens ) is a species of drongo found across the Indian Subcontinent. Like other members of the family Dicruridae, they are insectivorous and mainly black in colour, but with a white belly and vent. Young birds are, however, all black and may be confused with the black drongo, which is smaller and more compact in appearance. The subspecies found in Sri Lanka has white restricted to the vent.
The size of the birds varies clinally with northern birds larger. The extent of white on the underside also declines with size although there is a lot of local variation. The Sri Lankan forms leucopygialis and insularis are darker than the Indian form and there is some intergradation within the Sri Lankan forms.The species is believed to be closely related to Dicrurus leucophaeus but has not be confirmed with molecular sequence studies.
Both the white-bellied drongo and the black drongo share a diploid chromosome number of 68.
The white-bellied drongo is a resident breeder in India and Sri Lanka. This species is usually found in dry scrub or open forests. The distribution is restricted to peninsular India south of the Himalayas and to the west of the Gangetic delta bounded on the west by the Aravallis.