Angola, Benin, Cameroon, Central African Republic, Congo [The Democratic Republic of the], Congo [The Democratic Republic of the], Côte dIvoire, Equatorial Guinea, Gabon, Ghana, Guinea, Guinea-bissau, Liberia, Nigeria, Sierra Leone, Sudan, Togo, Uganda.
Sierra Leone and south-eastern Guinea east to south-western Ghana and northern Togo, and south-eastern Nigeria east to extreme south-western Sudan (Bengengai) and Uganda, south to extreme north-western and north-eastern Angola (Cabinda, northern Lunda Norte) and central DRCongo.
 
Population
Estimated population is unknown (2010).
Lowland Sooty Boubou (Laniarius leucorhynchus) [XC283325]
by Bram Vogels from Kirimia, Semuliki National Park, Bundibugyo, Western Region, Uganda (call, song)
Lowland Sooty Boubou (Laniarius leucorhynchus) [XC834318]
by Martin St-Michel from Semuliki Forest NP, Uganda (call)
Subspecies
No subspecies.
Recent DNA analyses indicate that this species may be as closely related to the black-and-scarlet southern African Crimson-breasted Gonolek (Laniarius atrococcineus) as it is to the similarly all-black low-latitude Mountain Sooty Boubou (Laniarius poensis), Fulleborn's Boubou (Laniarius fuelleborni) and Slate-coloured Boubou (Laniarius funebris).