| Smartdata, s.r.o. | Prague |
| SmartEmailing | |
| SmartGIS, s.r.o. | Olomouc |
| SmartGuide | |
| SMARTLINK, s.r.o. | South Bohemian |
| Smartlook | |
| Smartsupp | |
| smartWEB | Prague |
| SMSmidlet | Prague |
| Socialbakers, a.s. | Prague |
| Socialsharks | |
| SofCon, spol. s r.o. | Prague |
| SOFTbit software, s.r.o. | |
| SOFTconsult, spol. s r.o. | |
| Softec CZ, spol. s r.o. | |
| SoftEU, s.r.o. | Plzeň |
| SoftHouse, s.r.o. | Plzeň |
| Softmarket, spol. s r.o. | Prague |
| Software Development Europe, s.r.o. | South Moravian |
| Software602, a.s. | Prague |
| Sokrates systems, s.r.o. | |
| Solarmont, s.r.o. | |
| SolarPartner, s.r.o. | |
| SoliCAD, s.r.o. | Central Bohemian |
| SolidVision | South Moravian |
| Some move, s.r.o. | |
| SONET, spol. s r.o. | |
| SoneTech, s.r.o. | |
| SOTIO Biotech a.s. | Prague |
| Sotio Biotech, a.s. | |
| Soulmates Ventures | |
| Sourcefabric o.p.s. | Prague |
| Sova net | South Moravian |
| Spaneco spol. s r.o. | Prague |
| Speednet, s.r.o. | Ústí nad Labem |
| SPEL, a.s. | Central Bohemian |
| SPELEX, spol. s r.o. | South Moravian |
| Spendee, a.s. | |
| SpiNet, a.s. | |
| SportPass | |
| Springtide Ventures, s.r.o. | |
| Sprintel, s.r.o. | |
| Sprinter-studio, s.r.o. | |
| Sprinx | |
| SPSOFT, s.r.o. | |
| Stable.cz | Liberec |
| Stadyum CRM | Prague |
| Stantum, s.r.o. | Prague |
| Star Lift | Prague |
| STARLIT, s.r.o. | Liberec |