| Suncode Sp. z o.o. | |
| Sunnet.pl | Pomeranian |
| Sunrise System | |
| Sunscrapers Sp. z o.o. | Masovian |
| SunSoft | Silesian |
| Suntech S.A. | Masovian |
| Superhot | |
| Supermedia Sp. z o.o. | Masovian |
| SuperMemo World Sp. z o.o. | Greater Poland |
| Support.pl Sp. z o.o. | Masovian |
| Supremo Sp. z o.o. | Greater Poland |
| Supremum SEO Sp. z o.o. | |
| Surfer Sp. z o.o. | |
| Surg-Tech Sp. z o.o. Sp. komandytowa | |
| Surprise.Design | Silesian |
| Surveily Sp. z o.o. | |
| Suwary S.A. | |
| ŚwidMAN S.C. | Lublin |
| Swift Apps Sp. z o.o. | |
| Swing Development Sp. z o.o. | Masovian |
| SWITSYS Information Technology | |
| Syften | |
| Sygnity S.A. | |
| Sykom | Subcarpathian |
| Sylius | |
| Symetria | Greater Poland |
| Synappse | |
| Syndicai | |
| Synektik S.A. | |
| Synergy Codes | |
| Synerway | Masovian |
| Synrise | Lesser Poland |
| Synthaverse S.A. | |
| Syntoil S.A. | |
| Syriusz Sp. z o.o. | Subcarpathian |
| System 2001 Sp. z o.o. | Masovian |
| System 3E | Masovian |
| System-3 Sp. z o.o. | Lublin |
| Systemart | Lesser Poland |
| SYSTEmEG | Lower Silesian |
| SYSTEmEG Net Sp. z o.o. | |
| Systemics-PAB | |
| Szczeciński Park Naukowo-Technologiczny | |
| Szkoła Biznesu Politechniki Warszawskiej | |
| Szkoła Główna Gospodarstwa Wiejskiego w Warszawie | Masovian |
| Szkoła Główna Handlowa w Warszawie | |
| Szkoła Wyższa Ekonomii i Zarządzania w Łodzi | |
| Szkoła Wyższa im. Pawła Włodkowica w Płocku | |
| T-Bull S.A. | |
| T-Matic Grupa Computer Plus Sp. z o.o. | Podlaskie |