Pacific coast and coastal slope from southern Colombia (south-western Cauca) south through coastal lowlands of Ecuador (inland as far as southern Loja) and Peru (where also in upper Marañón Valley) to northern Chile (desert valleys of Aricaâ€"Parinacota).
 
Population
Estimated population is unknown (2010).
Chestnut-throated Seedeater (Sporophila) [XC155495]
by Niels Krabbe from Ca\u00f1ete, Lima Region, Peru (song)
Chestnut-throated Seedeater (Sporophila telasco) [XC336410]
by Cristian Pinto from Valle del rio Lluta, XV Region, Chile (song)
Subspecies
No subspecies.
Chestnut-throated Seedeater (Sporophila telasco) and Tumaco Seedeater (Sporophila insulata) (Sibley and Monroe 1990, 1993) have been lumped into Sporophila telasco following SACC (2006).
Molecular evidence suggests that genus is closely related to Oryzoborus, which should perhaps be subsumed within it. Further, that both genera should be placed in the tanager family (Thraupidae). Taxonomic status of "Sporophila insulata" (known only from Tumaco I, off Nariño, in south-western Colombia), with rufous rump and underparts, is uncertain: possibly a subspecies of present species, or a mutant population, or a hybrid with Ruddy-breasted Seedeater (Sporophila minuta). Further study is required.