| Numab Therapeutics AG | |
| Numaco AG | Aargau |
| Numarics AG | |
| Numbrs AG | Zurich |
| Nutrix AG | |
| NXI Therapeutics AG | |
| Nym Tehnologies S.A. | |
| O.I.S.A. GmbH | Basel-Landschaft |
| Oberli Engineering GmbH | Bern |
| Oberon microsystems AG | Zurich |
| Object XP AG | Zurich |
| Objectif l'une.ch S.A. | Fribourg |
| ObsEva | |
| Obtic Solutions Internet | Vaud |
| OC Oerlikon Management AG | Schwyz |
| Occlutech Holding AG | |
| Octapharma AG | |
| Octave 2 GmbH | Bern |
| OctaveSoft GmbH | Basel-Stadt |
| Octopus lab | Bern |
| Oculis S.A. | |
| Oculox Technologies S.A. | |
| Oekosoft AG | Zurich |
| Oetiker+Partner AG | Solothurn |
| Office Improvement GmbH | Zurich |
| Office World AG | Zurich |
| OfficeCare AG | Valais |
| OfficeWest AG | Aargau |
| Offisoft | Ticino |
| Olympe | |
| Olympic Banking System | Geneva |
| OM Pharma Ltd | |
| OMA3 | |
| OMEX AG | Zurich |
| Omicron Web-Services S.A. | Vaud |
| Omikron Data AG | Glarus |
| Omne Possibile | |
| Omni Ray AG | Zurich |
| Omnidata | |
| Omnis - Olivier Müller Networks & Internet Services | Zurich |
| OMrun | Zurich |
| Omya AG | |
| Oncompass GmbH | |
| One 4 You IT GmbH | Zurich |
| One Inside Switzerland AG | Basel-Landschaft |
| One Net GmbH | St. Gallen |
| Onebyte AG | Zurich |
| Oneconsult International AG | Zurich |
| Oneday AG | |
| Onena Medicines AG | |