Unenlagia (meaning "half-bird" in Latinized Mapudungun) is a genus of dromaeosaurid theropod dinosaur that lived in South America during the Late Cretaceous period.

The generic name is derived from Mapuche uñùm, 'bird', and llag, 'half', in reference to the fact that the describers considered the species to be a link between birds and more basal theropods.

[9] Likewise, the interpretation of the head form has changed from a shorter-snouted dromaeosaurid condition to the elongated shape known from the later discovered related genera Buitreraptor and Austroraptor.

[10] This conformed to a later hypothesis by Philip Senter that non-avian theropods like Unenlagia were unable to lift their forelimbs above their back, as even would still have been the case for the basalmost bird Archaeopteryx.

[11] South American workers have remained unconvinced though, countering that a laterally positioned scapula would make the coracoid of Unenlagia jut into its ribcage, which seems anatomically implausible.

[7] Novas and Puerta in the original description considered Unenlagia a sister taxon of the birds, which would make it a basal member of the Avialae sensu Gauthier 1986.