A raven is any of several larger-bodied passerine bird species in the genus Corvus. These species do not form a single taxonomic group within the genus. There is no consistent distinction between crows and ravens. Names are assigned to different species chiefly based on their size.

The largest raven species are the common raven and the thick-billed raven; these are also the largest passerine species.

The term "raven" originally referred to the common raven (Corvus corax), the type species of the genus Corvus, which has a larger distribution than any other species of Corvus, ranging over much of the Northern Hemisphere.

The modern English word raven has cognates in all other Germanic languages, including Old Norse (and subsequently modern Icelandic) hrafn and Old High German (h)Raban, all of which descend from Proto-Germanic *hrabanaz.

The collective noun for a group of ravens is an "unkindness". In practice, most people use the more generic "flock".