Burundi, Congo [The Democratic Republic of the], Eritrea, Ethiopia, Kenya, Malawi, Rwanda, Tanzania [United Republic of], Uganda, Zambia.
Extreme south-central Eritrea south to central and southern Ethiopia; eastern DRCongo, south-western Uganda, Rwanda and Burundi; Mt Elgon (Uganda-Kenya border) and western and central Kenya; north-eastern and southern Tanzania (Eastern Arc Mts); and north-eastern Zambia and northern Malawi (Nyika Plateau).
 
Population
Estimated population is unknown (2010).
Slender-billed Starling (Onychognathus tenuirostris) [XC125865]
by Andr\u00e1s Schmidt from Luwalo-area, Ndundulu forest, Udzungwa Mts., Tanzania (song)
Slender-billed Starling (Onychognathus tenuirostris) [XC703490]
by Josh Engel from Bufumbira (near Kanaba), Wilaya ya Kisoro, Mkoa wa Magharibi, Uganda (call)
Subspecies
Proposed subspecies theresae (described from northern Aberdares, in Kenya) considered largely inseparable from birds in rest of species' range.
The following 2 subspecies are recognised:
tenuirostris (Rüppell, 1836) - Eastern.
theresae Meinertzhagen, R, 1937 - Eastern Democratic Republic of the Congo to Kenya, Tanzania and northern Malawi.