The gray vireo (Vireo vicinior) is a small North American passerine bird. It breeds from the southwestern United States and northern Baja California to western Texas. It is a migrant, wintering in northwestern Mexico in western Sonora state, and the southern Baja Peninsula in Baja California Sur; it remains all year only in Big Bend National Park in southwest Texas. It is usually found at altitudes between 400 and 2,500 metres (1,300 and 8,200 ft) in its Mexican breeding grounds. This vireo frequents dry brush, especially juniper, on the slopes of the southwestern mountains.