- Language: Ona
- Alternate names: Aona, Selknam, Shelknam
- Language code: ona
- Language family: Chonan, Insular Chonan
- Number of speakers: 2 (Year 1991), now extinct
Ona is a language that was once spoken by the Selknam people in Isla Grande de Tierra del Fuego in southernmost South America.
The language is synthetic and the verb forms are made up of affixes.
The inflected verb forms and the word order distinguish the subject from object. The word order is normally OVS (object - verb - subject).