| SuperSEO | |
| Supplies Service Partner B.V. | South Holland |
| Supportware | North Brabant |
| Supreme Hosting | |
| SureSync | |
| Surfix Diagnostics | |
| Surfly | |
| Surfshark B.V. | |
| Surtronic | North Holland |
| SVM | North Brabant |
| Swan | |
| Swanbridge Capital | South Holland |
| Swapphone Europe B.V. | |
| Swets | South Holland |
| Swinth | South Holland |
| SwipeGuide | North Holland |
| Swis | South Holland |
| SWW.nl | South Holland |
| Swydo | |
| Sycada | North Holland |
| Sylics | Utrecht |
| Symeres | Gelderland |
| Symphony Solutions | North Holland |
| Symphony.live | |
| Sympower | |
| Symson | |
| Synaffix B.V. | |
| Synaxion B.V. | North Brabant |
| Syndy B.V. | |
| Synerga B.V. | South Holland |
| Synergy Health Utrecht B.V. | |
| Synerkine Pharma | |
| Synerscope | |
| Synetic | |
| Synobsys Nederland B.V. | South Holland |
| Syntess Software B.V. | South Holland |
| Syntho | |
| Syren Retail Security B.V. | Gelderland |
| Sysqa | Utrecht |
| SystematIC | South Holland |
| Systemation | Utrecht |
| Systemec B.V. | Limburg |
| Systony B.V. | South Holland |
| Sytec B.V. | South Holland |
| T-ICT | Utrecht |
| T-Minus Engineering B.V. | |
| T-Mobile Netherlands B.V. | South Holland |
| Taal & Digitaal | |
| Tabs & Spaces | |
| Tacta B.V. | |