Mountains in south-eastern Nigeria, north-western Cameroon, western Angola (Mt Moco); Bioko (Fernando Póo); also Albertine Rift in eastern Zaire, western Uganda, Rwanda and Burundi, and mountains in Kenya, Tanzania, north-eastern Zambia, Malawi and northern Mozambique (Mt Namuli).
 
Population
Estimated population is unknown (2010).
Bar-tailed Trogon (Apaloderma vittatum) [XC514420]
by Louis A. Hansen from Dibililo camp, Mafwemiro forest, Mpwapwa, Dodoma Region, Tanzania (call)
Bar-tailed Trogon (Apaloderma vittatum) [XC182164]
by Jacob C. Cooper from Buhoma, Bwindi Impenetrable Forest, Uganda (call)
Subspecies
Population in western half of Africa sometimes separated subspecifically as camerunense, and birds from Bioko (Fernando Póo) occasionally further separated as francisci, but characters apparently not constant for either of these forms.
The following 2 subspecies are recognised:
vittatum Shelley, 1882 - South-eastern Nigeria and western Cameroon; central Angola; Uganda and eastern DR Congo; Kenya to Mozambique.
camerunensis Reichenow, 1902 - Nigeria, Cameroon, and Bioko to Angola, western Democratic Republic of the Congo, and western Uganda.