| Oracle SQL Developer | Oracle Unbreakable Linux | Oracle Unified Method |
| Oracle Weblogic Server | Oracle WebLogic Server | Oracle9i |
| Oracular Spectacular | Orage | Oral Fixation 2 |
| Oral Fixation Tour | Oral Fixation Vol. 2 | Oral Fixation Vol. 2 (альбом) |
| Oral Fixation, Vol. 2 | Oral Fixation, Vol. 2 (альбом) | Oral history |
| Oral-B | Oramel Hinckley Simpson | Orange |
| Orange (значения) | Orange (манга) | Orange Armenia |
| Orange Bowl | Orange Box | Orange Business Services |
| Orange Caramel | ORANGE CARAMEL | Orange County Choppers |
| Orange County, Florida | Orange County, Indiana | Orange County, New York |
| Orange County, North Carolina | Orange County, Texas | Orange County, Vermont |
| Orange County, Virginia | Orange GGN | Orange Goblin |
| Orange Israel | Orange Juice | Orange Moldova |
| Orange Prokom Open | Orange Prokom Open 2007 | Orange Range |
| ORANGE RANGE | Orange Romeda | Orange SA |
| Orange Tiga | Orange Warsaw Open | Orangeburg |
| Orangeburg County, South Carolina | OrangeCD Player | Orangina |
| Orania | Orano | Orapia |
| Oratio principis | Oratosquilla oratoria | Oravec |
| Orazio Fiume | Orazio Vecchi | Orígenes |
| Orb | Orb (браузер) | Orbcomm-G2 |
| Orbea | Orbest | Orbigny |
| Orbiliaceae | Orbiliales | Orbiliomycetes |
| Orbiniidae | Orbis terrae | Orbis terrarum |
| Orbit | Orbit (жевательная резинка) | Orbit Books |
| Orbit Downloader | Orbit@home | Orbital |
| Orbital (альбом) | Orbital (значения) | Orbital ATK |
| Orbital Sciences | Orbital Sciences Corporation | Orbital Skyhook |
| Orbiter | Orbiter (значения) | Orbiter (БПЛА) |
| Orbitum | Orbix | Orc |
| Orc (Warcraft) | Orca | ORCA |
| Orca (альбом) | Orca Airways | Orca Browser |
| Orca orca | OrCAD | Orcaella |
| Orcaella brevirostris | Orcaella heinsohni | Orchesella erpeldingae |
| Orchesella hoffmanni | Orchestra Baobab | Orchestral Manoeuvres in the Dark |
| Orchid | Orchid (альбом) | Orchidaceae |
| Orchidales | Orchidantha | Orchidoideae |
| Orchipedum | Orchipedum (Orchidaceae) | Orchis |
| Orchis albertii | Orchis albida | Orchis anthropophora |
| Orchis athensis | Orchis × stevenii | Orchis ×stevenii |
| Orchis bifolia | Orchis blephariglottis | Orchis carpetana |
| Orchis cassidea | Orchis chlorotica | Orchis collina |
| Orchis convallariifolia | Orchis coreosmus | Orchis coriophora |
| Orchis cucullata | Orchis dulukae | Orchis elegans |
| Orchis erubescens | Orchis fedtschenkoi | Orchis fragrans |
| Orchis fuchsii | Orchis incarnata | Orchis intermedia |
| Orchis knorringiana | Orchis kotschyi | Orchis lanigera |
| Orchis leucoglossa | Orchis linearis | Orchis maculata |
| Orchis martrinii | Orchis mascula | Orchis merovensis |
| Orchis militaris | Orchis moria | Orchis morio |
| Orchis nervulosa | Orchis odoratissima | Orchis officinalis |
| Orchis pallens | Orchis palustris | Orchis persica |
| Orchis polliniana | Orchis punctulata | Orchis purpurea |
| Orchis pyrenaica | Orchis russowii | Orchis saccata |
| Orchis salina | Orchis sanasunitensis | Orchis simia |
| Orchis skorpili | Orchis smithii | Orchis spitzelii |
| Orchis stevenii | Orchis tephrosanthos | Orchis tridentata |
| Orchis triplicata | Orchis turkestanica | Orchis umbrosa |
| Orchis ustulata | Orchis zoophora | Orcinus |
| Orcinus orca | Orcs | Orcs & Humans |
| Orcs (Warcraft) | Orculidae | Orcutt |
| Ord | Ordem e Progresso | Ordem e progresso |
| Order & Chaos Online | Order by | ORDER BY (SQL) |
| Order of St Michael and St George | Order of the British Empire | Order of the Companions of Honour |
| Order of the Leech | Order Of The Leech | Order of War |
| Order of war | Order-in-Council | Ordered binary decision diagram |
| Ordet | Ordettes | Ordina Open |
| Ordina Open 2006 | Ordina Open 2007 | Ordina Open 2008 |
| Ordina Open 2009 | Ordinal Name | Ordinary Love |
| Ordinary World | Ordinatio imperii | Ordinatio Imperii |
| Ordnance QF 17 pounder | Ordnance QF 2 pounder | Ordnance QF 2-pounder |
| Ordnance QF 20 pounder | Ordnance QF 25 pounder | Ordnance QF 37 mm Mk I |
| Ordnance QF 6 pounder | Ordnung muss sein | Ordnungsdienst |
| Ordnungspolizei | ORDO | Ordo Ad Chao |
| Ordo Clericorum Regularium Pauperum Matris Dei Scholarum Piarum | Ordo Fratrum Praedicatorum | Ordo Regnum Sathanas |
| Ordo Rosarius Equilibrio | Ordo Templi Orientis | ORDVAC |
| Ore Monogatari!! | Ore no Imōto ga Konna ni Kawaii Wake ga Nai | Ore no Imouto ga Konna ni Kawaii Wake ga Nai |
| Ore no Imouto ga Konna ni Kawaii Wake ga Nai. | Ore no Imouto ga Konnani Kawaii Wake ga Nai | Ore no Kanojo to Osananajimi ga Shuraba Sugiru |
| Ore no Nounai Sentakushi ga, Gakuen Lovecome o Zenryoku de Jama Shiteiru | Ore wa, kimi no tame ni koso shini ni iku | Oreailurus jacobita |
| Oreailurus jacobitus | Oreamnos | Oreamnos americanus |
| Oreanthes | Oreas canna | Oreas martiana |
| Oreasteridae | Orectognathiti | Orectognathus |
| Orectolobidae | Orectolobiformes | Orectolobus |
| Orectolobus floridus | Orectolobus halei | Orectolobus hutchinsi |
| Orectolobus japonicus | Orectolobus leptolineatus | Orectolobus maculatus |
| Orectolobus ornatus | Orectolobus parvimaculatus | Orectolobus reticulatus |
| Orectolobus wardi | OreGairu | Oregon |
| Oregon Ballet Theatre | Oregon Country | Oregon County, Missouri |
| Oregon Trail | Oregon-grape | Oreimo |
| Oreina | Oreina alpestris | Oreiro |
| Oreiscelio | Orejuela | Orel Art |
| Orel Hershiser | Orel Leonard Hershiser IV | Orellana |
| Orelvis Perez Mitjans | Oren Lavie | Orenair |
| Orenburg | Orenda Aerospace | Orenda Engines |
| Orenda Iroquois | Oreo | Oreochromis aureus |
| Oreochromis mossambicus | Oreochromis niloticus | Oreodaphne californica |
| Oreoderus bhutanus | Oreoleuciscus humilis | Oreoleuciscus potanini |
| Oreomyrma | Oreomystis | Oreonax |
| Oreonax flavicauda | Oreophrynella | Oreophrynella quelchii |
| Oreophysa | Oreophysa microphylla | Oreopithecus bambolii |
