Dwarf Vireo is restricted to southwestern Mexico. It primarily occurs in the interior, from Jalisco and southern Guerrero south to central Oaxaca (Miller et al. 1957, Howell and Webb 1995). Dwarf Vireo probably is resident throughout most of not all of its range. Phillips (1962, 1968, 1991) suggested that it nests in "low, arid breeding grounds" and then migrates to higher elevations, a supposition that has not been confirmed. Howell and Webb (1995) suggest the possibilty that northern breeders may move to the Pacific slope in winter.
The elevational range of Dwarf Vireo is 1000-2500 m (Howell and Webb 1995, Parker et al. 1996).
Dwarf Vireo first was collected in 1826 by Ferdinand Deppe, but this specimen was overlooked until Alan Phillips identified it ca 140 years later (!) (Stresemann 1954, Philips 1968). Nelson (1898) consequently was unaware of Deppe's specimen when Nelson collected the type specimen of Vireo nelsoni in 1892. Dwarf Vireo "disappeared" again until it was collected in the mid 20th century (Miller et al. 1957).