| Samara | Madrid |
| SAMELAN. Soluciones Tecnológicas, S.L. | Madrid |
| Samsung Electronics Iberia, S.A. | Madrid |
| Sanabre Comunica | Barcelona |
| Sangar Computer, S.L. | Badajoz |
| Sanifit | Balearic Islands |
| Santa Clara Tech | Madrid |
| Santa Mónica Soluciones Informáticas | León |
| Santana Jerez, S.L. | Las Palmas |
| Santander X | Madrid |
| SAPAS Consulting, S.L. | Barcelona |
| Sapiens Talent | Madrid |
| SAPIMSA | Madrid |
| Saqqara Informática | Madrid |
| Sare-Berri | Gipuzkoa |
| Sarenet | Biscay |
| SareSoft Aplicaciones on Line, S.L. | Biscay |
| SareTech | Navarre |
| Sarpanet | Cantabria |
| SAT CIT | Madrid |
| Satdata | A Coruña |
| SATEC | Madrid |
| Sateliot | Barcelona |
| Satinfo, S.L. | Barcelona |
| Satlantis | |
| Satydal Comunicaciones | Málaga |
| Sauco Consulting | Zaragoza |
| SBA Informática | Valencia |
| SBSS Consulting, S.A. | Barcelona |
| SC Trade Technologies | Barcelona |
| Scaled Robotics | Barcelona |
| Scalian Spain | Madrid |
| Scan96 | Madrid |
| Scati Labs, S.A. | Zaragoza |
| Scoreapps | Madrid |
| Scytl Election Technologies, S.L.U. | Barcelona |
| Scytl Secure Electronic Voting, S.A. | Barcelona |
| SDi | La Rioja |
| SDi Digital Group | La Rioja |
| Sea and Air Technology, S.L. | Madrid |
| Seabery | Huelva |
| Seaya | |
| Seaya Ventures | Madrid |
| Secel Tecnològics, S.L. | Barcelona |
| Secíber Hardfrank, S.L. | Badajoz |
| Secuoyas | Madrid |
| SEDDI | Madrid |
| Seed&Click | Barcelona |
| SeedRocket | Barcelona |
| Seedtag | Madrid |