| Ragusa |
| Ras al-Khaimah |
| Réunion |
| Rewah |
| Rhineland-Palatinate |
| Rhineland Republic |
| Rhode Island |
| Rhodesia, Northern |
| Rhodesia, Southern |
| Rhodesia and Nyasaland |
| Rhodesia |
| Riau |
| Rif |
| Rio de Janeiro |
| Río de la Plata |
| Rio Grande do Norte |
| Rio Grande do Sul |
| Riouw |
| Roman Republic |
| Romania |
| Rondônia |
| Roraima |
| Russian Empire (till 1917) |
| Soviet Russia (1917-1922) |
| Russia (since 1991) |
| Russia, Northern (1918-1919) |
| Russia, Southern (1919-1921) |
| Rwanda |
| Ryukyu |