| Staply | |
| StarForce Content | |
| StarForce Technologies | Moscow |
| Start Hub Коворкинг | |
| start2up | Moscow |
| Startech | |
| Startpack | Moscow |
| StartTrack | Moscow |
| Startup Magic | Moscow |
| Startup Network | Moscow |
| Startup Tour | Moscow |
| Startup Village 2025 | Moscow |
| Statanly Technologies | |
| State Academic University for the Humanities | |
| State University of Education | |
| State University of Management | |
| State University of Maritime and Inland Shipping named after Admiral S.O. Makarov | |
| State University of Maritime and Inland Shipping" named after Admiral S. O. Makarov | |
| Steadyhost | Moscow |
| Steklov Mathematical Institute of Russian Academy of Sciences | |
| Stimulsoft | Smolensk |
| Stoik Software | Moscow |
| StormWall.pro | |
| Storytelling Software | Rostov |
| StudyApp | |
| StudyApps | |
| Sunmedia studio | Krasnodar |
| Sunrav Software | Moscow |
| Surprise Me | |
| SV-Soft | Moscow |
| SvyazKomplekt | Moscow |
| SWS | Voronezh |
| SWTecNN, LLC | |
| Synergetica | Donetsk People's Republic |
| Synergy Innovations | Moscow |
| SysDev Laboratories | Donetsk People's Republic |
| Sysinfo Lab | Tambov |
| SYSsoft | Moscow |
| Systech | Kaliningrad |
| Systemz | |
| Syzran-Soft | Moscow |
| T&D Systems, Inc. | Pskov |
| T8 Company | |
| Taiga System | |
| Tavrical National University - Faculty of Mathematics | Crimea |
| TealTech Capital | Moscow |
| Teamcoding | |
| TeamLead Conf | |
| Teamo.ru | |
| TechAudit LLC | |