- Octapharma France
- Ohre Pharma
- Olympe Pharma
- OM Pharma S.A.
- Omega Pharma France
- Omrix Biopharmaceuticals
- Opella Healthcare France SAS
- Orchard Therapeutics Netherlands BV
- Organon France
- Organon SA
- Origin Biosciences
- Orion Corporation
- Orion Pharma
- Orpha Devel Handels Vertriebs GmbH
- Orphalan SAS
- Orphan Europe
- Orphelia Pharma SAS
- Otsuka Pharmaceutical France SAS