- O.C.P.
- O.S.I
- Oasis
- Obione
- Océopin
- Oclam
- OCP Répartition
- Odost
- Odysud
- Oenobiol
- Officina Urban Therapy
- OGUST - SAS PAPPA
- OLBO
- Olfa
- Oligo Santé
- Olisma
- Olla
- Omega Pharma France
- Omron Healthcare France
- Omron Santé France
- Onagrine
- Oniris SAS
- Ontex France
- Opella Healthcare France SAS
- Ophrys Médica
- Ophtalmic B&T
- OptimaBio
- OptimHal-ProtecSom
- Optimiz
- Orgakiddy
- Orgalys SAS
- Organon France
- Orion Corporation
- Orkyn
- Ormendes SA
- Ornis - Ecuphar
- Orthonov
- Orthosoft
- Ortis
- Osalia
- Osato Europe
- Oscare
- Oscience
- Osilab
- OTC Concept
- OTC Médical
- Ouest Médical Diffusion
- Outremer
- Owen Mumford
- Oxypharm
- Oystershell Laboratories
