Extreme southern Bolivia (south-western Santa Cruz), western Paraguay, northern Argentina (south to eastern La Rioja, northern San Luis, central Córdoba and northern Buenos Aires) and south-western Uruguay.
 
Population
Estimated population is unknown (2010).
Little Thornbird (Phacellodomus sibilatrix) [XC49925]
by Bernabe Lopez-Lanus from Estancia El Potrero, Gualeguaychu, Entre Rios, Argentina (song)
Little Thornbird (Phacellodomus sibilatrix) [XC92191]
by Rosendo Manuel Fraga from Campo Ademar Dri zona eucalipto grande, 7 Km Sur de Federaci\u00f3n, Federaci\u00f3n, Entre R\u00edos, Argentina, Argentina (call, song)
Subspecies
No subspecies.
Considered by some authors to form a superspecies with Rufous-fronted Thornbird (Phacellodomus rufifrons), but the two overlap considerably in distribution, and differ in body size and nest structure.