| R&A Marketing | Madrid |
| RA-MA, S.A. | Madrid |
| Radian Systems | Madrid |
| Raimonster | |
| Rand App | Barcelona |
| Randal Systems, S.L. | Málaga |
| Raster Desarrollos Informáticos | Salamanca |
| RatedPower | Madrid |
| RavalCo | Barcelona |
| RawData | Valencia |
| React Alicante | |
| Reactiva | |
| ReadyCell, S.L. | Barcelona |
| Real Academia de Ciencias | Madrid |
| Real Academia Española | |
| Real Centro Universitario Escorial - María Cristina | |
| 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 |
| Reclamador | |
| 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 |
| Redbus, S.L. | Murcia |
| Redecom, Soluciones Informáticas para Empresas, S.L.L. | Madrid |
| Redegal, S.A. | |
| 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 |
| Redsauce Engineering Services, S.L. | |
| Redsys Servicios de Procesamiento, S.L. | Madrid |
| RedUSERS | Madrid |
| Reevoluciona | Madrid |
| Refineria Web, S.L. | Balearic Islands |