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.
This vireo frequents dry brush, especially juniper, on the slopes of the southwestern mountains. It has only one small region where it is a resident bird, the Big Bend National Park in the Rio Grande river valley of southwest Texas.
The Gray Vireo is 14 cm (5½ inches) in length, gray above, and dull white below, with a single faint wing bar and eye-ring. It has a short, thick bill. Sexes are similar. The sideways twitching of its tail is unique among vireos and is reminiscent of that of gnatcatchers. The call is hu-wee, chu-wee, che-weet, chee, ch-churr-weet, churr, schray.