| Code | Continent | Name | Population |
| ROM | Europe | Romania | 22,455,500 |
| RUS | Europe | Russian Federation | 146,934,000 |
| RWA | Africa | Rwanda | 7,733,000 |
| SAU | Asia | Saudi Arabia | 21,607,000 |
| SDN | Africa | Sudan | 29,490,000 |
| SEN | Africa | Senegal | 9,481,000 |
| SGP | Asia | Singapore | 3,567,000 |
| SGS | Antarctica | South Georgia and the South Sandwich Islands | 0 |
| SHN | Africa | Saint Helena | 6,000 |
| SJM | Europe | Svalbard and Jan Mayen | 3,200 |
| SLB | Oceania | Solomon Islands | 444,000 |
| SLE | Africa | Sierra Leone | 4,854,000 |
| SLV | North America | El Salvador | 6,276,000 |
| SMR | Europe | San Marino | 27,000 |
| SOM | Africa | Somalia | 10,097,000 |
| SPM | North America | Saint Pierre and Miquelon | 7,000 |
| SSD | Africa | South Sudan | 12,340,000 |
| STP | Africa | Sao Tome and Principe | 147,000 |
| SUR | South America | Suriname | 417,000 |
| SVK | Europe | Slovakia | 5,398,700 |