| RatedPower | Madrid |
| RavalCo | Barcelona |
| RawData | Valencia |
| ReadyCell, S.L. | Barcelona |
| Real Academia de Ciencias | Madrid |
| Real Academia Española | |
| Real Academia Galega | |
| Real Deal Milk | Barcelona |
| Real Energy Systems, S.L. | Madrid |
| Realiza.net | Barcelona |
| RealizacionWeb | Barcelona |
| Rebellion Pay | Madrid |
| Recdata Servicios IT, S.L.U. | Madrid |
| ReciKla, S.L. | Valencia |
| Recomiend.app, S.L. | Madrid |
| Recover Center | Madrid |
| Recovery Labs | Madrid |
| Recursos en la Red, S.L. | Alicante |
| RED Creativos | Málaga |
| Red Points | Barcelona |
| Red.es | Madrid |
| redacta.me | Salamanca |
| Redacta.me | Salamanca |
| Redbus, S.L. | Murcia |
| Redecom, Soluciones Informáticas para Empresas, S.L.L. | Madrid |
| Redes & Telecom | Barcelona |
| Redes Digitales de Telecomunicacion en Internet, S.L. | Zaragoza |
| Redes en Banda Ancha, S.L. | Murcia |
| Redes Informáticas | Santa Cruz de Tenerife |
| REDESSA | Tarragona |
| RedGiga, S.L. | A Coruña |
| RedIRIS | |
| Redline Asesores | Biscay |
| Redline Solutions, S.L.U. | |
| RedondoWS | Madrid |
| Redsys Servicios de Procesamiento, S.L. | Madrid |
| RedUSERS | Madrid |
| Reevoluciona | Madrid |
| Refineria Web, S.L. | Balearic Islands |
| Rehasoft, S.L. | Barcelona |
| Relevant Traffic | Madrid |
| Renta 4 Banco, S.A. | |
| Rentals United | Barcelona |
| Rentasoft S.A. | Sevilla |
| Rentservice Informática, S.L.U. | Madrid |
| Reparanet | Madrid |
| Replicalia, S.L. | Barcelona |
| República Web | Valencia |
| Residència d'Investigadors | |
| Retinset, S.L. | Barcelona |