| SertesLab | Moscow |
| Sesame Software | Moscow |
| Seven Winds Studio | Krasnodar |
| Sevhosting.net | Sevastopol |
| SF Education | |
| Shara-Soft | Moscow |
| Sherlock Platform | |
| Shop-GSM.ru | Moscow |
| Shop-inet | Moscow |
| Shop-profit | Moscow |
| Shopingtime | Moscow |
| Shtab | |
| Shvetsov technologies | |
| SibCode | |
| Sibers Ltd | Novosibirsk |
| SibSoft Ltd | Novosibirsk |
| Sigma Technology | Moscow |
| SilverAge Software | Moscow |
| SimbirSoft | Ulyanovsk |
| SIMETRA | |
| Simple Machines Russian Community | Moscow |
| SimpleFinance | |
| Sistema VC | Moscow |
| SiteNetwork | Nizhny Novgorod |
| Sitronics Group | |
| SkillFactory | |
| Skolkovo Innovation Center | Moscow |
| Skolkovo Institute of Science and Technology | Moscow |
| SKY Binary Art | Donetsk People's Republic |
| Skyeng | |
| Skylink | |
| SlavSSoft | Moscow |
| Smart Checkout | |
| Smart Label | |
| SmartDec | |
| SmartMerch | |
| SmartPrice | |
| SmartProgress | |
| SmartQuant | Saint Petersburg |
| Smartseeds | |
| Smartum IT | |
| SmartWeb | Moscow |
| Sobolev Institute of Mathematics | Novosibirsk |
| Sociate.ru | |
| Soft News Portal | Moscow |
| Soft Planeta | Moscow |
| Soft Service Company | Stavropol |
| Soft-Buy | Moscow |
| Soft-Center Data Recovery | Moscow |
| Soft-Hard.ru | Moscow |