Oraon Sadri
Orejón
Oring
Oriya (individual language)
Oriya (macrolanguage)
Orizaba Nahuatl
Orma
Ormu
Ormuri
Oro
Oroch
Oroha
Orok
Orokaiva
Oroko
Orokolo
Oromo
Oroqen
Orowe
Oro Win
Oruma
Orya
Osage
Osatu
Oscan
Osing
Ososo
Ossetian
Otank
Ot Danum
Oti
Otoro
Ottawa
Ottoman Turkish (1500-1928)
Otuho
Otuke
Ouma
Oune
Owa
Owenia
Owiniga
Oy
Oya'oya
Oyda
Oyster Bay Tasmanian
Ozolotepec Zapotec
Ozumacín Chinantec
Pa'a
Pááfang
Paakantyi
ISO 639-3 Reference Names