The red-eyed vireo (Vireo olivaceus) is a small American songbird, 13–14 cm (5.1–5.5 in) in length. It is somewhat warbler-like but not closely related to the New World warblers (Parulidae). Common across its vast range, this species is not considered threatened by the IUCN. "Vireo" is a Latin word referring to a green migratory bird, perhaps the female golden oriole, possibly the European greenfinch. The specific olivaceus is New Latin for olive-green, from Latin oliva "olive".