- Oak Ridge National Laboratory [Oak Ridge]
- Objets communicants pour l'Internet du futur
- Océ-Technologies B.V.
- Old Dog Consulting Ltd
- Open Universiteit Nederland [Heerlen]
- Open University of Cyprus
- Open University of Israël
- Open University of the Netherlands [Heerlen]
- Orange Labs
- Orange Labs R&D [Rennes]
- Orange Labs [Chatillon]
- Orange Labs [Meylan]
- Orange Labs [Paris]
- Orange Labs [Sophia Antipolis]
- Organisation for Economic Co-operation and Development
- Osaka University
- Osaka University [Osaka]
- Oslo and Akershus University College of Applied Sciences [Oslo]
- Osnabrück University of Applied Sciences
- Otto-von-Guericke-Universität Magdeburg = Otto-von-Guericke University [Magdeburg]
- OutSystems
- Oxford Brookes University
- Örebro University
- Örebro University School of Business