| Country Names | ISD Codes |
| Saint Helena | +290 | |
| Saint Kitts and Nevis | +1 | |
| Saint Lucia | +1 | |
| Saint Pierre and Miquelon (Collectivité territoriale de la République | +508 | |
| Saint Vincent and the Grenadines | +1 | |
| Samoa (Independent State of) | +685 | |
| San Marino (Republic of) | +378 | |
| Sao Tome and Principe (Democratic Republic of) | +239 | |
| Saudi Arabia (Kingdom of) | +966 | |
| Senegal (Republic of) | +221 | |
| Seychelles (Republic of) | +248 | |
| Sierra Leone | +232 | |
| Singapore (Republic of) | +65 | |
| Slovak Republic | +421 | |
| Slovenia (Republic of) | +386 | |
| Solomon Islands | +677 | |
| Somali Democratic Republic | +252 | |
| South Africa (Republic of) | +27 | |
| Spain | +34 | |
| Sri Lanka (Democratic Socialist Republic of) | +94 | |
| Sudan (Republic of the) | +249 | |
| Suriname (Republic of) | +597 | |
| Swaziland (Kingdom of) | +268 | |
| Sweden | +46 | |
| Switzerland (Confederation of) | +41 | |
| Syrian Arab Republic | +963 | |
