| O2 Czech Republic | O2 Tsjekkia | O2 World |
| O2 World (Berlin) | O2 World Hamburg | O3 |
| O3 helse | O3 helseeffekt | O3 helseeffekter |
| OA | Oa | Oa.no |
| Oažžejohka | Oadby and Wigston | Oahcesaisuolo naturreservat |
| Oahcesaisuolu naturreservat | Oahe-demningen | Oahedemningen |
| OAHR | Oahu | Oahu (Hawaii) |
| Oahu County | Oahu, Hawaii | Oahuhonningeter |
| OAI | OAIS-modellen | OAIX |
| Oak | OAK | Oak (prøvesprengning) |
| Oak Creek | Oak Creek (Wisconsin) | Oak Creek kraftverk |
| Oak Creek, Wisconsin | Oak Forest | Oak Forest (Illinois) |
| Oak Forest, Illinois | Oak Grove (Alabama) | Oak Harbor |
| Oak Harbor (Washington) | Oak Harbor, Washington | Oak Hill (Alabama) |
| Oak Lawn | Oak Lawn (Illinois) | Oak Lawn, Illinois |
| Oak Park | Oak Park (Illinois) | Oak Park (Michigan) |
| Oak Park, Illinois | Oak Park, Michigan | Oak Ridge |
| Oak Ridge (Tennessee) | Oak Ridge Lutheran Church | Oak Ridge National Laboratory |
| Oak Ridge Observatory | Oak Ridge, Tennessee | OAKA |
| OAKB | Oakdale | Oakdale (California) |
| Oakdale (Minnesota) | Oakdale, California | Oakdale, Minnesota |
| Oakey oljekraftverk | Oakham | Oakland |
| Oakland (California) | Oakland Bay Bridge | Oakland County |
| Oakland internasjonale flyplass | Oakland internasjonale lufthavn | Oakland Motor Car Company |
| Oakland oljekraftverk | Oakland Park | Oakland Park (Florida) |
| Oakland Park, Florida | Oakland Raiders | Oakland Raiders i NFL-sesongen 2018 |
| Oakland Raiders i NFL-sesongen 2019 | Oakland, California | Oakley |
| Oakley (California) | Oakley Arctic Challenge | Oakley, California |
| Oakman (Alabama) | Oakville | Oakville (Ontario) |
| Oakville, Ontario | Oakwell Stadium | Oakwood University |
| Oalgasj | Oalgásj | Oalgásj (fjelltopp) |
| Oalgejohka | Oalsgata | Oalsgata (Sandnes) |
| Oamaru | OAMS | Oana |
| Oana Andeea Manea | Oana Andreea Manea | Oana Şoit |
| Oana Bondar | Oana Borș | Oana Bors |
| Oana Carmina Bondar | Oana Carmina Herman | Oana Chirila |
| Oana Chirilă | Oana Doina Borș | Oana Doina Bors |
| Oana Șoit | Oana Florica Șoit | Oana Florica Soit |
| Oana Herman | Oana Manea | Oana Pantelimon |
| Oana Soit | Oana-Doina Bors | Oanes |
| Oanes-Lauvvik | Oannes | OAO DnB NOR Monchebank |
| OAPEC | OAR | OAR under Vinter-OL 2018 |
| Oarabile Babolayi | Oarddojávri | Oarisma |
| Oarje-Borgašgáisá | Oarjjevuodna | Oarjjit Cáskinjohsuorgi |
| Oarjjit Dáččavuotna | Oarjjit Mánabaisuorgi | Oarjjit Mássuorbmi |
| Oarjjit Nuorevuotna | Oarjjit Sieidda | Oarotrechus |
| OAS | Oase | OASE-bevegelsen |
| Oasebevegelsen | Oasen bydelssenter | Oasen Kjøpesenter |
| Oasen skole | Oasen Skole | Oasen skole Grenland |
| Oasen Storsenter | Oasen storsenter | Oaseteorien |
| Oasis | Oasis (band) | Oasis (forskningsstasjon) |
| Oasis Of The Seas | Oasis of the Seas | Oates Coast |
| Oates forlandsbre | Oates Land | Oath Bound |
| Oatlands Palace | OAU | Oaul Xu Zhenjiang |
| OAuth | Oaxaca | Oaxaca (by) |
| Oaxaca (delstat) | Oaxaca by | Oaxaca de Juarez |
| Oaxaca de Juárez | Oaxacadalen | Oaxacanthaxia |
| Oaxen Skärgårdskrog | Oğuz (distrikt) | Oğuz Sırmalı |
| Oğuzeli | Oğuzhan Asiltürk | Oğuzhan Özyakup |
| Oğuzhan Tüzün | Oğuzlar | Oazis (forskningsstasjon) |
| Ošljak | Oţelul Galaţi | Oððasat |
| Oñati | O´ Horten | O´Horten |
| Oøy | Oṃ maṇi padme hūṃ | Oļegs Antropovs |
| Ođag | Ođđajohka | Ođđajohka (Utsjok) |
| Ođđasat | Oświęcim | O’ Horten |
| O’boy | O’Brian Nyateu | O’Brien County |
| O’Brien Island | O’Brien-ætten | O’Dayne Richards |
| O’Fallon | O’Fallon (Illinois) | O’Fallon (Missouri) |
| O’G3NE | O’Hare internasjonale lufthavn | O’Haru |
| O’Higgins | O’Horten (filmmusikk) | O’Learys |
| O’Malley of the Mounted (1921) | O’Martins | O’Neal Nunataks |
| O’Neill-stipendiet | O’odham | O’Reilly Media |
| O’Sullivan | Ob | OB |
| Ob (andre betydninger) | Ob (by) | Ob (elv) |
| Ob (flere betydninger) | Ob etom zabyvat nelzja | OB Odense |
| OB-buss | Ob-La-Di, Ob-La-Da | OB-stjerne |
| OB/GYN | Oba | Obada Al-Kasbeh |
| Obadele Thompson | Obadias | Obadius |
| Obadja | Obadja (bok) | Obadjas bok |
| Obafemi Martins | Obafemi Owode | Obages |
| Obaid Al Jasmi | Obaid Al-Jasmi | Obaidullah Akhund |
| Obaidullah Akhund Mullah Obaidullah | Obalno-kraška | Obama |
| Obama, Barack | Obama-administrasjonen | Obama-regjeringen |
| Obamabukta | Obamacare | Obamagate |
| Oban | Oban (New Zealand) | Oban (whisky) |
| Obando | Obania | OBAS |
| Občanská demokratická strana | Obélix | Obóz Narodowo-Radykalny |
| Obbola | Obbola Ångsågs | Obbola Ångsågs AB |
| Obbukta | Obdorsk | Obduksjon |
| Obdulio Varela | Obdurodon | OBE |
| Obed | Obed Enamorado | Obedkulturen |
| Obedperioden | Obedska bara | Obelerio degli Antenori |
| Obelisk | Obelisk Mountain | Obeliskjordfly |
| Obeliskskipet | Obelix | Oben am jungen Rhein |
| Obenbergerula | Obento | Ober Ost |
| Ober-Eschbach bybanestasjon | Oberalp-pass | Oberalp-passet |
| Oberalppass | Oberalppasset | Oberammergau |
| Oberamt Ravensburg | Oberappellationsgericht | Oberösterreich |
| Oberösterreich (historisk) | Oberösterreich-Alpene | Oberösterreichische Voralpen |
| Oberösterreichs flagg | Oberbaumbrücke | Oberbayern |
