| St. Helena | SH | SHN | 654 |
| St. Kitts and Nevis | KN | KNA | 659 |
| St. Lucia | LC | LCA | 662 |
| St. Pierre and Miquelon | PM | SPM | 666 |
| St. Vincent and the Grenadines | VC | VCT | 670 |
| Samoa, Independent State of | WS | WSM | 882 |
| San Marino, Republic of | SM | SMR | 674 |
| Sao Tome and Principe, Democratic Republic of | ST | STP | 678 |
| Saudi Arabia, Kingdom of | SA | SAU | 682 |
| Senegal, Republic of | SN | SEN | 686 |
| Serbia and Montenegro | CS | SCG | 891 |
| Seychelles, Republic of | SC | SYC | 690 |
| Sierra Leone, Republic of | SL | SLE | 694 |
| Singapore, Republic of | SG | SGP | 702 |
| Slovakia (Slovak Republic) | SK | SVK | 703 |
| Slovenia | SI | SVN | 705 |
| Solomon Islands | SB | SLB | 090 |
| Somalia, Somali Republic | SO | SOM | 706 |
| South Africa, Republic of | ZA | ZAF | 710 |
| South Georgia and the South Sandwich Islands | GS | SGS | 239 |
| Spain, Spanish State | ES | ESP | 724 |
| Sri Lanka, Democratic Socialist Republic of | LK | LKA | 144 |
| Sudan, Democratic Republic of the | SD | SDN | 736 |
| Suriname, Republic of | SR | SUR | 740 |
| Svalbard & Jan Mayen Islands | SJ | SJM | 744 |
| Swaziland, Kingdom of | SZ | SWZ | 748 |
| Sweden, Kingdom of | SE | SWE | 752 |
| Switzerland, Swiss Confederation | CH | CHE | 756 |
| Syrian Arab Republic | SY | SYR | 760 |
