| Severo | | se-VE-ro | Italian, Spanish | |
| Sigfrido | | seeg-FREE-do (Italian), seeg-FREE-dho (Spanish) | Italian, Spanish | |
| Silvestre | | seel-BE-stre (Spanish) | Spanish, Portuguese | |
| Silvia | | SEEL-vyah (Italian), SEEL-byah (Spanish) | Italian, Spanish, Portuguese, Romanian, Slovak, English, German, Late Roman, Roman Mythology | |
| Silvio | | SEEL-vyo (Italian), SEEL-byo (Spanish) | Italian, Spanish, Portuguese, Croatian | |
| SimÓN | | see-MON | Spanish | |
| Socorro | | - | Spanish | |
| SofÍA | | so-FEE-ah | Spanish | |
| Sofronio | | - | Spanish | |
| Sol (1) | | - | Spanish, Portuguese | |
| Soledad | | so-le-DHAHD | Spanish | |
| Sonia | | SON-yə (English), SAWN-yə (English), SO-nyah (Italian) | English, Italian, Spanish, Portuguese, Romanian | |
| Soraya | | - | Persian, Spanish, French | |
| Sosimo | | so-SEE-mo | Spanish | |
| Susana | | soo-SAH-nah (Spanish) | Spanish, Portuguese | |