| Siemen | | SEE-mən (Dutch) | Dutch, Frisian | |
| Sieuwerd | | SOO-ərt | Dutch | |
| Silke | | ZIL-kə (German) | German, Dutch | |
| Silvester | | sil-VES-tər (English) | Dutch, English, Slovene, Slovak, German, Late Roman | |
| Simon | | SIE-mən (English), see-MAWN (French), ZEE-mawn (German), SEE-mawn (Dutch) | English, French, Swedish, Norwegian, Danish, German, Dutch, Hungarian, Slovene, Romanian, Macedonian | |
| Sjaak | | SHAH:K | Dutch | |
| Sjakie | | SHAH-kee | Dutch | |
| Sjef | | SHEF | Dutch | |
| Sjoerd | | SHOORT (Dutch) | Frisian, Dutch | |
| Sjors | | SHAWRS | Dutch | |
| Sofie | | zo-FEE (German), so-FEE-e (Danish), so-FEE (Dutch) | German, Danish, Dutch, Czech | |
| Sonja | | ZAWN-yah (German), SON-yah (Finnish) | German, Dutch, Swedish, Norwegian, Danish, Icelandic, Finnish, Slovene, Serbian, Croatian, Macedonia | |
| Sophie | | so-FEE (French), SO-fee (English), ZO-fee (German) | French, English, German, Dutch | |
| Staas | | STAH:S | Dutch | |
| Stef | | STEF | Dutch | |