| Spyrosoft S.A. | Lower Silesian |
| SpyShelter | Lesser Poland |
| Square One Resources Ltd | |
| Squares | |
| SSI - Agencja Interaktywna | West Pomeranian |
| sStore | Silesian |
| SSW Pragmatic Solutions | |
| Stabilis | |
| Standard Polish Enterprise SPE IMEX Sp. z o.o. | Łódź |
| Star Telecom Sp. z o.o. | Lublin |
| Starfax Polska Sp. z o.o. | Masovian |
| Starter Gdański Inkubator | |
| StartSmart Central & Eastern Europe | |
| Startup Art | |
| Startup Development House Sp. z o.o. | |
| Startup Founders | |
| Startup House | Masovian |
| Startup Hub Poland | Masovian |
| Startup Poland | Masovian |
| Startup School | |
| Startup Spark | |
| Startup Wrocław | Lower Silesian |
| Stary Pecet Serwis Komputerowy | Masovian |
| StatConsulting Sp. z o.o. | Masovian |
| Statlook | Lesser Poland |
| StatSoft Polska Sp. z o.o. | Lesser Poland |
| STATUS Starter | |
| Stava S.A. | |
| STELLIS | |
| Stepapp Sp. z.o.o. | |
| Sterlift Jerzy Roo | Masovian |
| Stermedia | |
| Sterowniki.pl Sp. z o.o. | Masovian |
| StethoMe Sp. z o.o. | |
| Stevedesign | |
| Stevia Automation Group Sp. z o.o. | |
| Stigo Sp. z o.o. Sp. k. | |
| StorkJet | |
| Storm IT | |
| Storware Sp. z o.o. | |
| Story Design | Masovian |
| Storymode | |
| Stowarzyszenie Jakości Systemów Informatycznych | Masovian |
| Stowarzyszenie Miłośników Internetu INDS | Silesian |
| Stowarzyszenie Wytwórnia | |
| Strategiczni.pl Sp. z o.o. | |
| Streamsoft Sp. z o.o. Sp. k. | Lubusz |
| Streamsoft Sp. z o.o. Sp. K. | |
| Strefa GSM | Warmian-Masurian |
| Strix | |