Vireos are small passerine birds that are largely restricted to the New World. The tend to have dull greenish plumage. The genus Vireo consists of five clades and 30 species.

The "eye-ringed" group.
Black-capped Vireo, Vireo atricapillus
Cozumel Vireo, Vireo bairdi
St. Andrew Vireo, Vireo caribaeus
Yellow-winged Vireo, Vireo carmioli
Cassin's Vireo, Vireo cassinii
Thick-billed Vireo, Vireo crassirostris
Yellow-throated Vireo, Vireo flavifrons
White-eyed Vireo, Vireo griseus
Cuban Vireo, Vireo gundlachii
Hutton's Vireo, Vireo huttoni
Puerto Rican Vireo, Vireo latimeri
Choco Vireo, Vireo masteri
Jamaican Vireo, Vireo modestus
Flat-billed Vireo, Vireo nanus
Dwarf Vireo, Vireo nelsoni
Blue Mountain Vireo, Vireo osburni
Mangrove Vireo, Vireo pallens
Plumbeous Vireo, Vireo plumbeus
Blue-headed Vireo, Vireo solitarius
Gray Vireo, Vireo vicinior

The "olivaceous" group.
Red-eyed Vireo, Vireo olivaceus
Noronha Vireo, Vireo gracilirostris
Yellow-green Vireo, Vireo flavoviridis (sometimes included in V. olivaceus)
Black-whiskered Vireo, Vireo altiloquus
Yucatan Vireo, Vireo magister

The "gilvus" group.
Warbling Vireo, Vireo gilvus
Brown-capped Vireo, Vireo leucophrys
Philadelphia Vireo, Vireo philadelphicus

Bell's Vireo - apparently basally positioned in Vireonidae.
Bell's Vireo, Vireo bellii

Clade uncertain.
Golden Vireo, Vireo hypochryseus
Slaty Vireo, Vireo brevipennis