O
- Odden, David A. (United States), phonology, African linguistics, Bantu languages
- Ohala, John (United States), phonetics, phonology
- Okrand, Marc (United States, 1948–), Klingon language, Mutsun language
- Ōno Susumu (Japan, 1919–2008), Japanese language, Tamil language
- Orešnik, Janez (Slovenia, 1935–), comparative linguistics
- Orikuchi Shinobu (Japan, 1887–1953), Japanese language
- Orton, Harold (UK, 1898–1975), phonology, dialectology, English dialects
- Osthoff, Hermann (Germany, 1847–1909), Indo-European studies, historical linguistics
- Ōtsuki Fumihiko (Japan, 1847–1928), Japanese language
Read more about this topic: List Of Linguists