Angola, Cameroon, Central African Republic, Congo [The Democratic Republic of the], Congo [The Democratic Republic of the], Côte dIvoire, Equatorial Guinea, Gabon, Ghana, Guinea, Liberia, Nigeria, Sierra Leone, Sudan, Togo, Uganda.
Southern Guinea and Sierra Leone east to southern Sudan and western Uganda, and south to north-western Angola and southern Zaire; also Bioko I (Fernando Póo).
 
Rarity Status
Currently this species is not classified as a rarity in this country OR information has not been updated.
Population
Estimated population is unknown (2010).
Black-casqued Hornbill (Ceratogymna atrata) [XC884138]
by Mike Nelson from Mipoundi, Lekoko, Haut-Ogooue, Gabon (?)
Black-casqued Hornbill (Ceratogymna atrata) [XC492864]
by Andres Angulo Rubiano from Lobeke National Park, Headquarters, Mambele, Cameroon (flight call)