| Oestrophasia uncana | Oestropsyche vitrina | Oestrus (chi ruồi) |
| Oesymna | Oetophorus clavatus | Oetophorus cornutus |
| Oetophorus koreensis | Oetophorus maculatus | Oetophorus naevius |
| Oetophorus obscurus | Oetophorus pleuralis | Oetophorus taiwanensis |
| Oetosis angustifolia | Oetosis blechnodes | Oetosis carnosa |
| Oetosis elongata | Oetosis ensiformis | Oetosis filiformis |
| Oetosis furcata | Oetosis isoetifolia | Oetosis lineata |
| Oetosis obtusa | Oetosis ophioglossodes | Oetosis rigida |
| Oetosis stipitata | Oetosis zosterifolia | Oettern |
| Oettersdorf | Oevenum | Oeversee |
| Oeyregave | Oeyreluy | Oezdemirus alternans |
| Oezdemirus teres | Of | Of June |
| Of June (EP) | Of June EP | Of Monsters and Men |
| Of the Night (bài hát) | Of, Trabzon | Ofaiston |
| Ofaiston monandrum | Ofakim | Ofatulena |
| OFB | OFC | OFC Champions League |
| OFC Nations Cup | OFC Nations Cup 2008 | OFC Nations Cup 2012 |
| OFDM | Ofena | Off the wall |
| Off the Wall | Off the Wall (album) | Off the Wall (bài hát) |
| Offa của Mercia | Offagna | Offanengo |
| Offekerque | Offemont | Offenau |
| Offenbach (huyện) | Offenbach am Main | Offenbach an der Queich |
| Offenbach-Hundheim | Offenbüttel | Offenberg |
| Offendorf | Offenhausen | Offenheim |
| Offerle, Kansas | Office 16 | Office 2016 |
| Office Open XML | Officers | Official Charts Company |
| Offida | Offignies | Offin |
| Offingen | Offlaga | Offlanges |
| Offline | Offoy, Oise | Offoy, Somme |
| Offranville | Offrethun | Offroicourt |
| Offshore leaks | Offshoring | Offstein |
| Offwiller | Oficanthon | Oficanthon mirabilis |
| Ofis, Kızıltepe | Ofköy, Bismil | Ofterdingen |
| Oftering | Ofterschwang | Oftia africana |
| Oftia revoluta | Oftringen | Ofu-Olosega |
| Ofusato | Oga, Akita | Ogallah, Quận Trego, Kansas |
| OGame | Ogan Ilir | Ogan Komering Ilir |
| Ogan Komering Ulu | Ogan Komering Ulu Selatan | Ogan Komering Ulu Timur |
| Oganesson | Ogasawara | Ogasawara Mitsuo |
| Ogastemma pusillum | Ogata Sadako | Ogawa Daiki |
| Ogawa Keijiro | Ogawa Kiyoshi | Ogawa Koki (cầu thủ bóng đá) |
| Ogawa Ryoya | Ogōri, Fukuoka | Ogéviller |
| Ogíjares | OGC | Ogcocephalidae |
| Ogcocephalus | Ogcocephalus corniger | Ogcocephalus darwini |
| Ogcocephalus radiatus | Ogcogaster (Ogcogaster) segmentator | Ogcogaster (Ogcogaster) tessellatus |
| Ogcogaster kempi | Ogcogaster kirbyi | Ogcogaster segmentator |
| Ogcogaster tessellata | Ogcogaster tessellatus | Ogden Nash |
| Ogden, Arkansas | Ogden, Illinois | Ogden, Iowa |
| Ogden, Kansas | Ogden, Quận Champaign, Illinois | Ogden, Quận Riley, Kansas |
| Ogdenia | Ogdenia mutilla | Ogdensburg, Wisconsin |
| Ogdoconta | Ogdoconta altura | Ogdoconta atomaria |
| Ogdoconta cinereola | Ogdoconta cymographa | Ogdoconta gamura |
| Ogdoconta justitia | Ogdoconta lilacina | Ogdoconta moreno |
| Ogdoconta musculus | Ogdoconta plumbea | Ogdoconta pulverulenta |
| Ogdoconta pulvilinea | Ogdoconta sexta | Ogdoconta tacna |
| Ogdoecosta | Ogdoecosta juvenca | Ogema, Minnesota |
| Ogema, Wisconsin | Ogenne-Camptort | Oger, Marne |
| Ogeu-les-Bains | Ogeum-dong | Oggaz |
| Oggebbio | Oggelshausen | Oggiona con Santo Stefano |
| Oggiono | Oggiyamduraipakkam | Oggy and the Cockroaches |
| Oggy et les Cafards | Oggy và những chú gián tinh nghịch | Oghuz (quận) |
| Ogi | Ogi Aritatsu | Ogi Kota |
| Ogi, Saga | Ogihara Takahiro | Ogilbia galapagosensis |
| Ogilbia pearsei | Ogilby's ghostshark | Ogilby's rainbowfish |
| Ogilvie, Minnesota | Ogilvy & Mather | Ogla Melha |
| Oglasa | Oglasa annulisigna | Oglasa ansorgei |
| Oglasa apicalis | Oglasa arcuata | Oglasa aroa |
| Oglasa atristipata | Oglasa aulota | Oglasa bifidalis |
| Oglasa bisignata | Oglasa calimanii | Oglasa captata |
| Oglasa chavenei | Oglasa clearchus | Oglasa closteroides |
| Oglasa collenettei | Oglasa confluens | Oglasa connectens |
| Oglasa consanguis | Oglasa contigua | Oglasa cornuta |
| Oglasa cosmiodes | Oglasa costimaculata | Oglasa costiplaga |
| Oglasa costisignata | Oglasa defixa | Oglasa dia |
| Oglasa diagonalis | Oglasa diasticta | Oglasa dufayi |
| Oglasa ecclipsis | Oglasa fulviceps | Oglasa fusciterminata |
| Oglasa griselda | Oglasa hollandi | Oglasa holophaea |
| Oglasa hypenoides | Oglasa iselaea | Oglasa junctisigna |
| Oglasa lagusalis | Oglasa lunifera | Oglasa maculata |
| Oglasa maculosa | Oglasa malagasy | Oglasa mediopallens |
| Oglasa microsema | Oglasa nana | Oglasa niloticus |
| Oglasa notabilis | Oglasa obliquilinea | Oglasa ochreobrunneata |
| Oglasa ochreovenata | Oglasa ozela | Oglasa pachycnemis |
| Oglasa parallela | Oglasa phaeonephele | Oglasa plagiata |
| Oglasa pomona | Oglasa prionosticha | Oglasa purpureotincta |
| Oglasa renilinea | Oglasa retracta | Oglasa rufimedia |
| Oglasa rufoaurantia | Oglasa sambawana | Oglasa separata |
| Oglasa sordida | Oglasa stygiana | Oglasa tamsi |
| Oglasa tessellata | Oglasa trigona | Oglasa umbrosa |
| Oglasa xanthorhabda | Oglasodes | Oglasodes atrisignata |
| Oglasodes bisinuata | Oglasodes nyasica | Ogle, Quận Somerset, Pennsylvania |
| OGLE-2005-BLG-169Lb | OGLE-2014-BLG-0124Lb | OGLE-2016-BLG-1195Lb |
| Oglesby, Illinois | Oglesby, Texas | Oglianico |
| Ogliastra | Ogliastra (tỉnh) | Ogliastro |
| Ogliastro Cilento | Ogloblinia | Ogloblinia keralaensis |
| Ogmodera albovittata | Ogmodera forticornis | Ogmodera kenyensis |
| Ogmodera lobata | Ogmodera multialboguttata | Ogmodera nigrociliata |
| Ogmodera sudanica | Ogmodera sulcata | Ogmoderidius aethiopicus |
| Ogmoderidius flavolineatus | Ogmoderidius gardneri | Ogmoderidius nebulosus |
| Ogmoderidius posthumeralis | Ogmodirus | Ogmodon vitianus |
