| Saving Cloud | |
| Sawicom | Greater Poland |
| Scalo Sp. z o.o. | |
| Scan and Buy | |
| Scanmed S.A. | |
| Schibsted Tech Polska | |
| Scientific | Masovian |
| Scope Fluidics | |
| Scramjet Sp. z o.o. | |
| ScrapingAnt | |
| Scrascom Sp. z o.o. | Masovian |
| Screen Network | |
| Scythe Studio Sp. z o.o. | |
| SDCLabs | |
| SDS Optic S.A. | |
| SDS Popławscy Sp. J. | Lower Silesian |
| SE16N | Masovian |
| Sebdan.pl | Łódź |
| Secfense Sp. z o.o. | |
| Securitum | |
| Security.pl | Masovian |
| SEDKOMP w Siedlcach Sp. z o.o. | Masovian |
| SEEDiA Sp. z o.o. | |
| SeekStorm Sp. z o.o. | Masovian |
| Seemore | |
| Seetop | Masovian |
| Selea | |
| Selectrin | |
| Self Learning Solutions Sp. z o.o. | |
| Selmo Sp. z.o.o. | |
| Selvita | |
| Semihalf | |
| Sempai | Podlaskie |
| Semrevo | |
| SEMSEI | |
| Sens.AI | |
| Sente | Lower Silesian |
| SEO Rank Monitor | Masovian |
| SEO4.net | Lesser Poland |
| SeoHost.pl | |
| Seoland | |
| Seris Konsalnet Holding S.A. | |
| Serv-net | |
| ServoCode Sp. z o.o. | |
| Servodata Elektronik Sp. z o.o. | Lublin |
| Serwis komputerowy | Masovian |
| Serwis komputerowy Olsztyn | Warmian-Masurian |
| Serwnet | Masovian |
| Setia.pl | Silesian |
| Sevenet S.A. | Masovian |