O'du
Odual
Odut
Ofayé
Official Aramaic (700-300 BCE)
Ofo
Ogbah
Ogbia
Ogbogolo
Ogbronuagum
Ogea
Oirata
Ojibwa
Ojitlán Chinantec
Okanagan
Okiek
Oki-No-Erabu
Okobo
Okodia
Oko-Eni-Osayen
Oko-Juwoi
Okolod
Okpamheri
Okpe (Northwestern Edo)
Okpe (Southwestern Edo)
Oksapmin
Oku
Old Aramaic (up to 700 BCE)
Old Avar
Old Breton
Old Burmese
Old Chinese
Old Cornish
Old Dutch
Old English (ca. 450-1100)
Old French (842-ca. 1400)
Old Frisian
Old Georgian
Old High German (ca. 750-1050)
Old Hittite
Old Hungarian
Old Irish (to 900)
Old Japanese
Old Kentish Sign Language
Old Korean (3rd-9th cent.)
Old Lithuanian
Old Manipuri
Old Marathi
Old Mon
Old Norse
ISO 639-3 Reference Names