| Serviceform | |
| Setera Communications Oy | |
| Sharetribe Oy | |
| Shipyard Games | |
| Sievo | |
| Sigmatic / Telia Inmics-Nebula Oy | Uusimaa |
| Siili Solutions | |
| Silo.AI | Uusimaa |
| SimAnalytics Oy | |
| Singa Oy | |
| Siniscape | |
| Siru Mobile | |
| Sirway | |
| SisuDigital | |
| Sitebuilders Finland Oy | Uusimaa |
| Skandal Technologies | Uusimaa |
| Skarta | |
| SkenarioLabs Oy | |
| SkenarioLabs Oy | |
| Skycode | |
| Skyfora | |
| Slap Media | Uusimaa |
| Slush | Uusimaa |
| Small Giant Games | Uusimaa |
| Smartbi | |
| Smartblock Oy | |
| Smartcom Labs | |
| Smartifik Oy | |
| Smartly.io Solutions Oy | |
| Smartpaper | |
| Smartvatten Oy | |
| Smoothly Oy | |
| Snapshop | |
| Sniffie Software Ltd | |
| Sofor Oy | South Ostrobothnia |
| Softability | Uusimaa |
| Softagram Oy | |
| Softman Oy | Ostrobothnia |
| Software Explosion Oy | Central Finland |
| Software Finland ry | |
| Solar Foods Oy | |
| Solar Water Solutions Oy Ltd | |
| Solid Immuno-Oncology Oy | |
| Solita | Uusimaa |
| Solteq | Uusimaa |
| Soma Pilvi | Kymenlaakso |
| Spacent | |
| Sparkmind.vc | |
| Specim, Spectral Imaging Ltd | |
| Spectarium Games | |