Cameroon, Congo [The Democratic Republic of the], Eritrea, Ethiopia, Kenya, Sudan, Tanzania [United Republic of], Uganda.
Eastern Sudan, Eritrea and western and central Ethiopia, south to extreme north-eastern Zaire, central Uganda, western Kenya and central-northern Tanzania; range expanding in western Kenya. Recently reported from northern Cameroon, so may occur in Central African Republic.
 
Population
Estimated population is unknown (2010).
Black-billed Barbet (Lybius guifsobalito) [XC300437]
by Andrew Spencer from Lake Awassa, Ethiopia (duet, song, duet song)
Black-billed Barbet (Lybius guifsobalito) [XC45092]
by James and David Bradley from Ethiopia Hotel, Gambella, Ethiopia (call, song)
Subspecies
Closely related to Black-collared Barbet (Lybius torquatus) (similar size, coloration, displays, sexual duet roles), but not so close as to form a superspecies. Each reacts strongly to playback of the other's voice. Also related, less closely, to Red-faced Barbet (Lybius rubrifacies). Birds become smaller clinally from north to south, but insufficient for racial differentiation. Populations from White Nile southwards formerly separated as subspecies ugandae.