| Ordina | Antwerp |
| Orditech S.A. | Hainaut |
| Organi | Antwerp |
| Ortus B.V.B.A. | East Flanders |
| OSG B.V.B.A. | Antwerp |
| OTN Systems N.V. | |
| Outwares S.P.R.L. | Walloon Brabant |
| Outwares S.R.L. | |
| Overbyte | Liège |
| Ovizio Imaging Systems N.V./S.A. | |
| Oxurion N.V. | |
| Oxynade N.V. | East Flanders |
| Paginaweb | Namur |
| Panasonic Energy Europe N.V. | Flemish Brabant |
| PANO-Solutions | |
| Paralax | Antwerp |
| Parfaitement web | Brussels-Capital |
| Parkwind | |
| PARSEC Accelerator | |
| Partnership for Advanced Computing in Europe | Brussels-Capital |
| Pass HR Services | |
| Patrice Decoeur | Liège |
| Paumar | Flemish Brabant |
| pb web concept | Namur |
| PC-Hulp.com | Flemish Brabant |
| PC-Matic | West Flanders |
| Penbox S.R.L. | |
| PeopleWare N.V. | Antwerp |
| PEPITe S.A. | Liège |
| Perceval | Brussels-Capital |
| Perceval Technologies sa-nv | Brussels-Capital |
| PH Systems B.V.B.A. | Flemish Brabant |
| Pharmony S.A. | |
| Pharrowtech | |
| PhenoSystems | Walloon Brabant |
| Pick-it N.V. | |
| Pigment | |
| PIKON Benelux N.V. | Limburg |
| Pincette B.V.B.A. | Flemish Brabant |
| Pioneer Europe NV | East Flanders |
| Pivott | Flemish Brabant |
| Piwisgraphics | Hainaut |
| Pixcell | Hainaut |
| Pixfactory | Namur |
| Pixular B.V. | West Flanders |
| Pixy.Family | Brussels-Capital |
| Planet-eco | |
| Planete Multimedia ASBL | Luxembourg |
| PlanningForce | Hainaut |
| Pluginvest | |