| older | mayor |
| oldest | mayor |
| Oldest child | Eldest |
| oldfashioned | anticuado |
| Oldfield Thomas | Oldfield Thomas |
| Oldham | Oldham |
| oldish | mayor |
| Oldly | Antigua |
| Oldman River | Río Oldman |
| Oldowan | Olduvayense |
| Oldschool jungle | Jungle |
| oldster | viejo |
| Olduvai Gorge | Garganta de Olduvai |
| Olduvai theory | Teoría de Olduvai |
| Olduwan | Olduvayense |
| Oldřich Duras | Oldřich Duras |
| Oldřich Nejedlý | Oldřich Nejedlý |
| Ole Bull | Ole Bull |
| Ole Einar Bjørndalen | Ole Einar Bjorndalen |
| OLE for process control | OPC |
| Ole Gunnar Solskjær | Ole Gunnar Solskjær |
| Ole Nydahl | Ole Nydahl |
| Ole Rømer | Ole Rømer |
| Ole von Beust | Ole von Beust |
| Ole Worm | Olaus Wormius |
| Oleaceae | Oleaceae |
| oleaginous | grasiento |
| oleander | adelfa |
| oleanders | adelfa |
| Olecko | Olecko |
| Oleg | Oleg |
| Oleg Blokhin | Oleg Blojín |
| Oleg Cassini | Oleg Cassini |
| Oleg Lisogor | Oleg Lisogor |
| Oleg Losev | Oleg Vladimirovich Losev |
| Oleg Menshikov | Oleg Menshikov |
| Oleg of Novgorod | Oleg |
| Oleg Penkovsky | Oleg Penkovsky |
| Oleg Salenko | Oleg Salenko |
| Oleg Serebrian | Oleg Serebrian |
| Oleguer Presas | Oleguer Presas |
| Oleksandr Shovkovskiy | Oleksandr Shovkovsky |
| Oleksandriia | Alejandría |
| Olenyok River | Olenyok |
| oleograph | oleografía |
| olfactory | olfatorio |
| olfactory pollution | contaminación olfativa |
| Olfactory system | Sistema olfativo |
| Olga | Olga de Kiev |
| Olga Aleksandrovna Ladyzhenskaya | Olga Ladyzhenskaya |
| Olga Bondarenko | Olga Bondarenko |
| Olga Bryzgina | Olga Bryzgina |
| Olga Gyarmati | Olga Gyarmati |
| Olga Knipper | Olga Leonardovna Knipper |
| Olga Konstantinovna of Russia | Olga Konstantinovna Romanova |
| Olga Korbut | Olga Korbut |
| Olga Nikolaevna of Russia | Olga Nikolayevna Romanova |
| Olga of Kiev | Olga de Kiev |
| Olga Preobrajenska | Olga Preobrajenska |
| Olgierd Zienkiewicz | Olgierd Zienkiewicz |
| Olhão | Olhão |
| olibanum | incienso |
| Oliebol | Oliebollen |
| Olifant | Olifante |
| oligarchic | oligárquico |
| oligarchy | oligarquía |
| Oligocene | Oligoceno |
| Oligochaeta | Oligochaeta |
| oligoelement | oligoelemento |
| Oligonucleotide | Oligonucleótido |
| oligopoly | oligopolio |
| Olimpia | Olimpia |
| Olimpia Asunción | Club Olimpia |
| Olimpia Milano | Olimpia Milano |
| Olimpija Ljubljana | NK Olimpija Ljubljana |
| Olimpiysky National Sports Complex | Estadio Olímpico de Kiev |
| Olimpo de Bahía Blanca | Club Olimpo |
| Olinda | Olinda |
| Olingo | Bassaricyon |
| Olinia | Oliniaceae |
| olive | oliva |
| Olive Baboon | Papio anubis |
| Olive Branch Petition | Petición de la rama de olivo |
| olive oil | aceite de oliva |
| olive oil mill wastewater | alpechín |
| olive tree | olivo |
| Olive Warbler | Peucedramus taeniatus |
| olive-tree | olivo |
| Olive-wood | Olea europaea |
| Oliveira | Olea europaea |
| Oliveira de Azeméis | Oliveira de Azeméis |
| Oliveira de Frades | Oliveira de Frades |
| Oliveira do Hospital | Oliveira do Hospital |
| Olivenza | Olivenza |
| Oliver | Olea europaea |
| Oliver Bierhoff | Oliver Bierhoff |
| Oliver Cromwell | Oliver Cromwell |
| Oliver Hardy | Oliver Hardy |
| Oliver Hazard Perry class frigate | Fragatas clase Oliver Hazard Perry |
| Oliver Heaviside | Oliver Heaviside |
| Oliver Hirschbiegel | Oliver Hirschbiegel |
| Oliver Joseph Lodge | Oliver Joseph Lodge |
| Oliver Kahn | Oliver Kahn |
| Oliver Neuville | Oliver Neuville |
| Oliver Norvelle Hardy | Oliver Norvelle Hardy |
| Oliver Riedel | Oliver Riedel |
| Oliver Sacks | Oliver Sacks |
| Oliver Smithies | Oliver Smithies |
| Oliver Stone | Oliver Stone |
| Oliver Tambo | Oliver Tambo |
| Oliver Twist | Oliver Twist |
| Oliverio Rincón | Oliverio Rincón |
| olives | aceitunas |
| Olivia | Olivia |
| Olivia de Havilland | Olivia de Havilland |
| Olivia Lewis | Olivia Lewis |
| Olivia Lufkin | Olivia |
| Olivia Newton-John | Olivia Newton-John |
| Olivia Trinidad Arias | Olivia Trinidad Arias |
| Olivier | Olea europaea |
| Olivier Besancenot | Olivier Besancenot |
| Olivier de la Marche | Olivier de la Marche |
| Olivier Grouillard | Olivier Grouillard |
| Olivier Messiaen | Olivier Messiaen |
| Olivier Panis | Olivier Panis |
| Olivier van Noort | Oliverio van Noort |
| Olivine | Olivino |
| Ollantaytambo | Ollantaytambo |
| Ollantaytambo District | Ollantaytambo |
| Olleros District | Distrito de Olleros |
| Ollersdorf im Burgenland | Ollersdorf im Burgenland |
| Olli Rehn | Olli Rehn |
| Ollie Johnston | Ollie Johnston |
| Ollon | Ollon |
| Olmec | Olmeca |
| Olmec hieroglyphs | Bloque de Cascajal |
| Olmeca | Olmeca |
| Olof Palme | Olof Palme |
| Olof Rudbeck the Younger | Olof Rudbeck el Joven |
| Olof Skötkonung | Olaf el Tesorero |
| Olof Swartz | Peter Olof Swartz |
| Olof Vilhelm Arrhenius | Olof Vilhelm Arrhenius |
| Oloid | Oloide |
| Olokun | Olokun |
| Olomouc | Olomouc |
| Olomouc District | Olomouc |
| Olomouc Region | Región de Olomouc |
| Olomouc Synagogue | Sinagoga |
| Olongapo City | Olóngapo |
| Olorus | Óloro |
| Olpe | Distrito de Olpe |
| Olsen Brothers | Olsen Brothers |
| Olsztyn | Olsztyn |
| OLT | Río Olt |
| Olt County | Olt |
| Olt River | Río Olt |
| Olten | Olten |
| Oltenia | Oltenia |
| Oltingen | Oltingen |
| Olusegun Obasanjo | Olusegun Obasanjo |
| Olybrius | Anicio Olibrio |
| Olympe de Gouges | Olympe de Gouges |
| Olympe Maxime | Olympe Maxime |
| Olympia | Olimpia |
| Olympiacos | Olimpiakos CFP |
| Olympiacos FC | Olimpiakos CFP |
| Olympiacos SC | Olimpiakos CFP |
| olympiad | olimpíada |
| Olympiakos | Olimpiakos CFP |
| Olympiakos Nicosia | Olympiakos Nicosia FC |
| Olympian | Estadio Olímpico de Atenas |
| Olympias | Olimpia de Epiro |
| Olympic | olímpico |
