Olumarachi
Olumarama
Olunyole
Olusamia
Olushisa
Olutsotso
Oluwanga
Omagua
Omaha-Ponca
Ombamba
Ombo
Omejes
Omi
Ömie
Omok
Omotik
Omurano
Ona
Oneida
One, Inebu
One, Kabore
One, Kwamtim
One, Molmo
One, Northern
One, Southern
Ong
Önge
Onin
Onin Based Pidgin
Oniyan
Onjob
Ono
Onobasulu
Onondaga
Ontenu
Ontong Java
Oorlams
Opao
Opata
Opuuo
Orang Kanaq
Orang Seletar
Orejón
Oring
Oriya, Adivasi
Oriya (individual language)
Oriya (macrolanguage)
Orma
Ormu
Ormuri
ISO 639-3 Inverted Names