| Obscuriphantes obscurus dilutior | Obscuriphantes pseudoobscurus | Obscuromyia westralica |
| Obscuropterus melanargyrea | Observatoire de Paris | Obsessed (bài hát của Mariah Carey) |
| Obsessed by Cruelty | Obsession (bài hát của Shayne Ward) | Obsidian |
| Obsonville | Obtegomeria | Obtegomeria caerulescens |
| Obterre | Obtrée | Obtuscampa |
| Obtusella | Obtusella erinacea | Obtusella intersecta |
| Obtusella lata | Obtusella macilenta | Obtusella orisparvi |
| Obtusella roseotincta | Obtusella tumidula | Obtusifolium |
| Obtusifolium obtusum | Obtusipalpis | Obtusipalpis albidalis |
| Obtusipalpis brunneata | Obtusipalpis citrina | Obtusipalpis fusipartalis |
| Obtusipalpis pardalis | Obtusipalpis rubricostalis | Obtusodonta foxleei |
| Obtusodonta manitobae | Obtusodonta obscuricolor | Obuchi Keizō |
| Obuchi Keizo | Obuchi Yūko | Obuchi Yuko |
| Obucola | Obukhiv | Obukhiv (huyện) |
| Obus arenosus | Obus capensis | Obus elizabethae |
| Obus infirmus | Obuz, Elâzığ | Obuz, Tatvan |
| Obuzbaşı, Mazgirt | Obvious (bài hát của Westlife) | Obwalden |
| Obwalden (bang) | Obyčtov | Obyekt 195 |
| Obyekt 279 | Obytce | Obzor |
| OC-14 | OC-14 Groza | OC-14-4A |
| OC-ute | Oca | Ocaña |
| Ocaña, Tây Ban Nha | Ocadia glyphistoma | Ocak, Aziziye |
| Ocak, Kemaliye | Ocak, Pazar | Ocak, Yomra |
| Ocakbaşı, Üzümlü | Ocakbaşı, Delice | Ocakbaşı, Erbaa |
| Ocakbaşı, Tutak | Ocaklar, Erdek | Ocaklı, Aşkale |
| Ocaklı, İdil | Ocaklı, Ödemiş | Ocaklı, Dinar |
| Ocaklı, Gelibolu | Ocaklı, Kars | Ocaklı, Maçka |
| Ocaklı, Mustafakemalpaşa | Ocaklı, Nazilli | Ocaklı, Pazar |
| Ocaklı, Sorgun | Ocaklı, Tuşba | Ocaklı, Van |
| Ocaklı, Varto | Ocaktaşı, Şebinkarahisar | Ocala, Florida |
| Ocalaria | Ocalaria cohabita | Ocalaria dioptica |
| Ocalaria guarana | Ocalaria macrops | Ocalaria oculata |
| Ocalaria pavina | Ocalaria pavo | Ocalaria quadriocellata |
| Ocalea (chi bọ cánh cứng) | Ocalemia borneensis | Ocalemia carpo |
| Ocalemia hayashii | Ocalemia vigilans | OCaml |
| Ocamonte | Ocampo, Chihuahua | Ocampo, Coahuila |
| Ocampo, Durango | Ocampo, Guanajuato | Ocampo, Michoacán |
| Ocampo, Tamaulipas | Ocana, Corse-du-Sud | Ocara |
| Ocaria | Ocarina | Ocauçu |
| Ocón | Ocú (huyện) | OCB |
| Ocb | OCB Bank | OCB Vietnam |
| Occagnes | Occapes distinctor | Occapes hinzi |
| Occapes sierrae | Occey | Occhiatana |
| Occhieppo Inferiore | Occhieppo Superiore | Occhiobello |
| Occia ashmeadi | Occia elegans | Occia pulchella |
| Occidental Mindoro | Occidental Mindoro (tỉnh) | Occidentalia |
| Occidentalia comptulatalis | Occidentophosis damarina | Occidozyga |
| Occidozyga baluensis | Occidozyga borealis | Occidozyga celebensis |
| Occidozyga diminutivus | Occidozyga floresiana | Occidozyga floresianus |
| Occidozyga laevis | Occidozyga lima | Occidozyga magnapustulosus |
| Occidozyga semipalmata | Occidozyga semipalmatus | Occidozyga sumatrana |
| Occidozyga vittatus | Occimiano | Occisor atratus |
| Occisor inscitus | Occisor versutus | Occitanie |
| Occitanosaurus | Occoches | Occupy Central |
| Occupy Wall Street | OCD | OCEAN |
| Ocean City, New Jersey | Ocean Eyes | Ocean Girl |
| Ocean Odyssey | Ocean Springs, Mississippi | Ocean Waves |
| Ocean's 8 | Ocean's Eleven (phim năm 2001) | Oceania Football Confederation |
| Oceanites | Oceanites gracilis | Oceanites gracilis galapagoensis |
| Oceanites gracilis gracilis | Oceanites oceanicus | Oceanites oceanicus exasperatus |
| Oceanites oceanicus oceanicus | Oceanodroma | Oceanodroma castro |
| Oceanodroma furcata | Oceanodroma furcata furcata | Oceanodroma furcata plumbea |
| Oceanodroma homochroa | Oceanodroma hornbyi | Oceanodroma jabejabe |
| Oceanodroma leucorhoa | Oceanodroma macrodactyla | Oceanodroma markhami |
| Oceanodroma matsudairae | Oceanodroma melania | Oceanodroma microsoma |
| Oceanodroma monorhis | Oceanodroma monteiroi | Oceanodroma tethys |
| Oceanodroma tethys kelsalli | Oceanodroma tethys tethys | Oceanodroma tristrami |
| Oceanopapaver | Oceanside, California | Ocella |
| Ocellochloa | Ocellochloa rudis | Ocenebra |
| Ocenebra acanthophora | Ocenebra brevirobusta | Ocenebra chavesi |
| Ocenebra erinacea | Ocenebra inornata | Ocenebra lumaria |
| Ocenebrinae | Ocenotrophon | Ocenotrophon painei |
| Ocentejo | Ochagavía | Ochagavia |
| Ochagavia andina | Ochagavia carnea | Ochagavia elegans |
| Ochagavia litoralis | Ochakiv | Ochakiv (huyện) |
| Ochancourt | Ochanostachys | Ochanostachys amentacea |
| Ochánduri | Ochersky (huyện) | Oches |
| Ochetarcha | Ochetodillo sulcatus | Ochetophila nana |
| Ochetophila trinervis | Ochetorhynchus | Ochetorhynchus andaecola |
| Ochetorhynchus melanurus | Ochetorhynchus melanurus atacamae | Ochetorhynchus melanurus melanurus |
| Ochetorhynchus phoenicurus | Ochetorhynchus ruficaudus | Ochetorhynchus ruficaudus famatinae |
| Ochetorhynchus ruficaudus montana | Ochetorhynchus ruficaudus ruficaudus | Ochey |
| Ocheyedan, Iowa | Ocheyedan, Quận Osceola, Iowa | Ochiai Hiroshi |
| Ochicanthon | Ochicanthon besucheti | Ochicanthon cambeforti |
| Ochicanthon ceylonicus | Ochicanthon cingalensis | Ochicanthon crockermontis |
| Ochicanthon crypticus | Ochicanthon danum | Ochicanthon deplanatus |
| Ochicanthon devagiriensis | Ochicanthon dulitmontis | Ochicanthon dytiscoides |
| Ochicanthon edmondsi | Ochicanthon ernei | Ochicanthon gangkui |
| Ochicanthon gauricola | Ochicanthon hanskii | Ochicanthon hikidai |
| Ochicanthon javanus | Ochicanthon karasuyamai | Ochicanthon kikutai |
| Ochicanthon kimanis | Ochicanthon laetus | Ochicanthon loebli |
| Ochicanthon maryatiae | Ochicanthon masumotoi | Ochicanthon mulu |
| Ochicanthon murthyi | Ochicanthon mussardi | Ochicanthon neglectus |
| Ochicanthon nitidus | Ochicanthon obscurus | Ochicanthon ochii |
| Ochicanthon oharai | Ochicanthon peninsularis | Ochicanthon punctatus |
| Ochicanthon rombauti | Ochicanthon takakui | Ochicanthon tambunan |
| Ochicanthon thai | Ochicanthon thailandicum | Ochicanthon tristis |
| Ochicanthon tristoides | Ochicanthon uedai | Ochicanthon vazdemelloi |
| Ochicanthon woroae | Ochimus laetipennis | Ochina |
| Ochina latrellii | Ochina ptinoides | Ochiobryum |
