South-eastern Brazil (north to Minas Gerais and Espírito Santo), Uruguay and north-eastern Argentina (Misiones south to Buenos Aires); southern populations winter north to south-central Brazil (southern Mato Grosso) and eastern Paraguay.
 
Population
Estimated population is unknown (2010).
Blue-billed Black Tyrant (Knipolegus cyanirostris) [XC45194]
by Marco Cruz from Estancia El Potrero (limite Norte), Gualeguaychu_Entre Rios, Argentina (call)
Blue-billed Black Tyrant (Knipolegus cyanirostris) [XC835362]
by Bernabe Lopez-Lanus from Bocaina de Minas, Minas Gerais, Brazil (song)