Breeds in south-western USA from Wyoming (occasional), central and eastern Utah, southern Nevada and southern California east, discontinuously, to western Colorado, northern and eastern Arizona, west, northern and south-eastern New Mexico and western Texas (Big Bend and adjacent areas), and north-western and northern Mexico (northern Baja California and northern Coahuila). Migrates to non-breeding areas from south-western Arizona south to north-western Mexico (western Sonora, southern Baja California) and in south-western Texas.
 
Population
Estimated population is 400,000 (2010).
Grey Vireo (Vireo vicinior) [XC181396]
by Lance A. M. Benner from Pigeon Spring, Slate Creek Divide, Maricopa County, Arizona, United States (song)
Grey Vireo (Vireo vicinior) [XC481043]
by Bobby Wilcox from Nye County, Nevada, United States (song)
Subspecies
No subspecies.
Has been suggested that dark birds with deep black bill from Nachoguero Valley (Baja California) and north-central Durango, in north-western Mexico, might represent a distinct subspecies.