| Selena | | - | Spanish, Russian, Greek Mythology (Latinized) | |
| Sence | | - | Medieval Spanish | |
| Sens | | - | Medieval Spanish | |
| Septima | | - | Ancient Roman, Spanish | |
| Serafina | | se-rah-FEE-nah (Polish) | Italian, Portuguese, Spanish, Polish | |
| Sergio | | SER-jo (Italian), SER-khyo (Spanish) | Italian, Spanish | |
| Seve | | SE-ve | Spanish | |
| Severiano | | se-ve-RYAH-no | Italian, Spanish | |
| Severino | | se-ve-REE-no (Italian, Spanish) | Italian, Spanish, Portuguese | |
| 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 | |