| oink | grogner |
| ointment | pommade |
| ointment for burns | onguent contre les brûlures |
| Oio Region | Oio |
| Oirats | Oïrats |
| Oireachtas | Oireachtas |
| Oise | Oise |
| Oise River | Oise |
| Oita | Oita |
| Oita Trinita | Oita Trinita |
| Ojamajo Doremi | Magical DoReMi |
| Ojen | Ojén |
| Ojos Así | Ojos Así |
| Ojos del Salado | Nevado Ojos del Salado |
| OK | OK |
| OK Budućnost Podgorica | Buducnost Podgorica |
| OK Go | OK Go |
| Ok Tedi River | Ok Tedi |
| Oka cheese | Oka |
| Oka River | Oka |
| okapi | okapi |
| Okapi Wildlife Reserve | Réserve de faune à okapis |
| OKATO | OKATO |
| Okavango Region | Okavango |
| Okavango River | Okavango |
| Okayama | Okayama |
| OKB | OKB |
| Okcheon County | Comté de Okcheon |
| Okean Elzy | Okean Elzy |
| Okeh Records | Okeh Records |
| Okhi Day | Jour du Non |
| Okhotny Ryad | Okhotny Ryad |
| Okhotsk | Okhotsk |
| Okhranka | Okhrana |
| Oki | Oki |
| Okina | Okina |
| Okinawa | Okinawa |
| Okinawa Island | Okinawa |
| Okinawan language | Okinawais |
| Okinotorishima | Okinotorishima |
| Okita Sōji | Sōji Okita |
| Oklahoma | Oklahoma |
| Oklahoma - Oklahoma City | Texas |
| Oklahoma City | Oklahoma City |
| Oklahoman | Oklahomien |
| Okondo | Okondo |
| Okonomiyaki | Okonomiyaki |
| Okopowa Street Jewish Cemetery | Cimetière juif de Varsovie |
| okra | gombo |
| Okrug | Okroug |
| Oksana Akinshina | Oksana Akinchina |
| Oksana Baiul | Oksana Baiul |
| Oksana Domnina | Oksana Domnina |
| Oksana Grishuk | Oksana Grishuk |
| Oksana Kazakova | Oksana Kazakova |
| Oksana Khvostenko | Oksana Khvostenko |
| Oktoberfest | Oktoberfest |
| Oku Yasukata | Yasukata Oku |
| Okuchichibu Mountains | Monts Okuchichibu |
| Okurigana | Okurigana |
| Okushiri Island | Île Okushiri |
| OL | OL |
| Ol Chiki script | Alphabet santâlî |
| Ol Doinyo Lengai | Ol Doinyo Lengaï |
| Ola Håkansson | Ola Håkansson |
| Olaberria | Olaberria |
