Inia is a genus of river dolphins from South America, containing one to four species.

The genus was described by Alcide d'Orbigny in 1834 when Delphinus geoffrensis, described by Henri Marie Ducrotay de Blainville in 1817, was recognized to be a unique taxon.

[3] Most of the scientific community accepted this single species classification, as does the IUCN.

[5] In 2014, the population in the Araguaia-Tocantins basin was proposed to define an additional species, Inia araguaiaensis,[6] but this remains debated.

The American Society of Mammalogists recognizes the highest number of species at four, although this is only tentative, pending further studies which could either confirm or deny the classification.