| Ono Toyo Golf Club | Ono | Hyogo |  Japani | inactive |
| Onomichi Country Club - Uneyama Course | Sera | Hiroshima | Japani | inactive |
| Onomichi Golf Club | Mihara | Hiroshima | Japani | inactive |
| Onomichi Uzushio Country Club | Onomichi | Hiroshima | Japani | inactive |
| Onondaga Golf and Country Club | Fayetteville | New York |  Yhdysvallat | inactive |
| Onsjö Golfklubb | Vänersborg | Västra Götaland |  Ruotsi | inactive |
| Onsøy Golfklubb | Manstad | Østfold |  Norja | inactive |
| Ontake | Kani | Gifu | Japani | inactive |
| Ontario Country Club | Ontario | New York | Yhdysvallat | inactive |
| Onteora Club | Tannersville | New York | Yhdysvallat | inactive |
| Ontonagon Golf Course | Ontonagon | Michigan | Yhdysvallat | inactive |
| Onuma Kokusai Country Club | Kayabe | Hokkaido | Japani | inactive |
| Onuma Lake Golf Club | Kayabe | Hokkaido | Japani | inactive |
| Onward Mangilao Golf Club | Mangilao | Guam |  Guam | inactive |
| Onward Talofofo Golf Club | Talafofo | Guam | Guam | inactive |
| Onwentsia Club | Lake Forest | Illinois | Yhdysvallat | inactive |
| Onyx | Grand Blanc | Michigan | Yhdysvallat | inactive |
| Oodate Country Club | Oodate | Akita | Japani | inactive |
| Ooka Golf Club | Kinosaki | Hyogo | Japani | inactive |
| Oonodai Golf Club | Akita | Akita | Japani | inactive |
| Oosaki Golf Club | Shida | Miyagi | Japani | inactive |
| Oost-Zuid | Nunspeet | Gelderland |  Alankomaat | inactive |
| Oost-Zuid | Groesbeek | Gelderland | Alankomaat | inactive |
| Oostwoud-Westwoud | Benthuizen | Zuid-Holland | Alankomaat | inactive |
| Ootacamund Gymkhana Golf Club | The Nilgiris | Tamil Nadu |  Intia | inactive |
| Ootaka | Housu | Ishikawa | Japani | inactive |
| Ootawara Golf Club | Nasu | Tochigi | Japani | inactive |
| Ooyodogawa Golf Course | Miyazaki | Miyazaki | Japani | inactive |
| Opal Cove Resort Golf Course | Coffs Harbour | New South Wales |  Australia | inactive |
| Open | Cotgrave | Nottinghamshire |  Englanti | inactive |
| Open | Dongguan | Guangdong |  Kiina | inactive |
| Open | Fingal | Victoria | Australia | inactive |
| Open 9 | Myrtle Beach | South Carolina | Yhdysvallat | inactive |
| OPEN GOLF St. Johann Alpendorf | Sankt Johann im Pongau | Salzburg |  Itävalta | inactive |
| Open Golf Zandvoort | Zandvoort | Noord-Holland | Alankomaat | inactive |
| Open.9 Golf Eichenried | Moosinning | Bavaria |  Saksa | inactive |
| Openbare Golfbaan Kralingen | Rotterdam | Zuid-Holland | Alankomaat | inactive |
| Openbare Golfclub Dronten | Dronten | Flevoland | Alankomaat | inactive |
| Oporto Golf Club | Espinho | Beira Litoral |  Portugali | inactive |
| Opotiki Golf Club | Opotiki | Bay of Plenty |  Uusi-Seelanti | inactive |
| Oppdal Golfklubb | Oppdal | Sør-Trøndelag | Norja | inactive |
| Oppegård Golfklubb | Oppegård | Akershus | Norja | inactive |
| Oppenheimer Golf Club | Welkom | Free State |  Etelä-Afrikka | inactive |
| Opunake Golf Course | Opunake | Taranaki | Uusi-Seelanti | inactive |
| Oquirrh Hills Golf Course | Tooele | Utah | Yhdysvallat | inactive |
| Ora Country Club | Jeju | Jeju |  Etelä-Korea | inactive |
| Orange | Savoy | Illinois | Yhdysvallat | inactive |
| Orange | Parrish | Florida | Yhdysvallat | inactive |
| Orange | Anseong | Gyeonggi | Etelä-Korea | inactive |
| Orange | Tomioka | Gunma | Japani | inactive |