- O.E.S. Medical Limited
- Obelis S.A., O.E.A.R.C.
- OBV Objektbau Bomers GmbH
- Occlutech GmbH
- Occupational & Medical Innovations Ltd.
- OCULUS Optikgeräte GmbH
- Oechsler AG
- OMRON Healthcare Europe B.V.
- OncoTherm Kft.
- Ontario Ministry of International Trade and Investment – International Trade Branch
- Ontex Healthcare
- Oostwoud International B.V.
- Opal Filmproduktion GmbH
- Operon S.A.
- OPHARDT Hygiene-Technik GmbH & Co. KG
- Ophtechnics Unlimited
- OPI Office de Promotion des, Industries et des Technologies
- Opitek International
- Opitz + Flierl Hospitaltechnik AG
- Oppo Medical Inc.
- OPT-Officina di Protesi Trento S.p.A.
- OPTI Medical Systems GmbH
- Optima Scandinavia AB
- Optiplan GmbH
- Optomed Ltd
- Optomic España, S.A.
- Önapi GmbH
- Ofa Bamberg GmbH
- Officine Meccaniche Pejrani S.r.l.
- Ogonek Research and Production Center
- Ohio Medical Corporation
- OHK Medical Devices
- Oiarso S. Coop.
- OK Biotech Co., Ltd.
- OKI Systems (Deutschland) GmbH
- OKM
- OKW Odenwälder Kunststoffwerke Gehäusesysteme GmbH
- OLIVER Medical Packaging B.V.
- Olsen Indústria e Comércio S/A
- Olympus Deutschland GmbH
- Omega Diagnostics Group Plc
- Omnia S.r.l.
- OmniVision Technologies, Inc
- OSATU, S. Coop.
- Osborn Somepic Technologie
- OSCAR Mil-TEK Ltd.
- Oscimed S.A.
- OSM Gesellschaft für offene Systeme in der Medizin mbH
- Osmetech Molecular Diagnostics
- OSTEOMED
- Osteometer MediTech, Inc.
- Osteosys Co., Ltd.
- Osyris Medical
- Otto Suhner AG
- Owen Mumford Ltd.
- Oxair Ltd., Oxygen Enrichment Systems
- Oxford Performance Materials, Inc. (OPM)
- Oxoid Ltd
- Oxylitre Ltd
- Oxymat A/S
- Oxy’Pharm
- OXYPLUS TECHNOLOGIE
- Oyster Bay Pump Works Inc.
- Ozonomatic System s.r.l.
- Ozu Corporation
- Optotek d.o.o.
- Oracle Deutschland GmbH
- Oraltech Instruments (Pvt) Ltd.
- Ordisi S.A.
- Oregon Bioscience Association
- Orfit Industries N.V.
- OrgaCard Siemantel & Alt GmbH
- ORIGIN 3D
- Oriola Oy
- Orion Health Ltd
- Orly General Supply S.r.l., Production & QA Dept.
- ORMED GmbH & Co. KG
- Orphée S.A.
- Ortho Care
- Ortho Select GmbH
- Ortho Tech Enterprises
- Orthopaedic Innovation Limited
- Ortner Reinraumtechnik GmbH