Angola, Botswana, Congo [The Democratic Republic of the], Djibouti, Eritrea, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Rwanda, Somalia, South Africa, Sudan, Swaziland, Tanzania [United Republic of], Uganda, Zambia, Zimbabwe.
Vagrant to Yemen.
Eritrea, Ethiopia, Djibouti, extreme south-eastern Sudan and north, western and southern Somalia south, patchily, to south-eastern DRCongo, Zambia, Malawi, extreme south-eastern Angola, north-eastern Namibia (Caprivi region), northern and eastern Botswana, Zimbabwe, northern and eastern South Africa, Swaziland and southern Mozambique.
 
Population
Estimated population is unknown (2010).
(Buphagus erythrorynchus) [XC645943]
by isaac kilusu from Makana Local Municipality (near Fort Brown), Western District, Eastern Cape, South Africa (call)
Red-billed Oxpecker (Buphagus erythrorynchus) [XC200771]
by Gabriel A. Jamie from Manyoni, Singida, Tanzania (call)
Subspecies
No subspecies.
Hybrids with Yellow-billed Oxpecker (Buphagus africanus) recorded in Zimbabwe. Birds from R Palala, in northern South Africa (eastern Limpopo Province), described as subspecies caffer, and birds from Panda, in southern Mozambique (Inhambane District), as subspecies scotinus, but both considered inseparable from birds in rest of species' range.
Other proposed subspecies include invictus (Somalia, north-eastern Kenya), angolensis (south-eastern Angola) and bestiarum (southern Zimbabwe).