| Nomitech | Attica |
| Nova | Attica |
| Nowhere Studio | |
| NTRATECH Ltd | |
| Nuevvo Webware P.C. | |
| Nummuspay | Attica |
| NUS Solutions | |
| Odyssey Venture Partners | Attica |
| OK!Thess | |
| Oktagon IKE | |
| OKTO | |
| Olympia Electronics | Attica |
| Omnicliq | |
| On-Line Data | Attica |
| ON.marketing | Attica |
| Onspot | Attica |
| Onyro.com | Attica |
| OpenCofee.gr | |
| Opencoffeee.gr | Attica |
| Openfund | Attica |
| OpenThessaloniki | Central Macedonia |
| OPT Hellas SA | Attica |
| Optima-X | |
| Optimum S.A. | Attica |
| Optisoft | Attica |
| Optiva LCS Hellas | |
| Optronics | Attica |
| Oracle Greece | Attica |
| Oramad | |
| Orgin Studios | Attica |
| OTEGLOBE S.A. | Attica |
| OTO Dev | |
| Oyster Hellas | |
| P. Moschopoulos & Co | Central Macedonia |
| PA Web Gate | Attica |
| Panasoft S.A. | |
| Panhellenic Association of Recognised Colleges | |
| Panou | Attica |
| Panteion University of Social and Political Sciences | |
| Pantso | Attica |
| Papaki | Crete |
| Paramarketing.gr | Attica |
| Patlis.com | Attica |
| Pavla S.A. | |
| PC Project | |
| PC-Shop | Attica |
| PC2Help | Attica |
| Petros Dimitriadis | Attica |
| PG-Software | Attica |
| Phaistos Networks | Attica |