- Open University of Madrid (UDIMA), Faculty of Social Sciences and Humanities DEQARINST5454 Facultad de Ciencias Sociales y Humanidades Spain
- Open University of Madrid (UDIMA), Faculty of Technical Sciences and Engineering DEQARINST5455 Facultad de Ciencias Técnicas e Ingeniería Spain
- Open University of Portugal DEQARINST2114 PT0015 Universidade Aberta Lisboa (Portugal)
- Open University of the Netherlands DEQARINST1727 NL0014 Open Universiteit Heerlen (Netherlands)
- Opole University of Technology DEQARINST1929 PL0140 Politechnika Opolska Opole (Poland)
- Osh State University DEQARINST5930 Ош мамлекеттик университети Osh (Kyrgyzstan)
- Osh Technological University DEQARINST5929 Ош технологиялык университети Osh (Kyrgyzstan)
- Oslo Metropolitan University DEQARINST1815 NO0069 Oslomet – storbyuniversitetet Oslo (Norway)
- Oslo National Academy of the Arts DEQARINST1805 NO0042 Kunsthøgskolen i Oslo Oslo (Norway)
- Oslo New University College DEQARINST7622 NO0076 Oslo Nye Høyskole Oslo (Norway)
- Osnabrück University DEQARINST0380 DE0067 Universität Osnabrück Osnabrück (Germany)
- Osnabrück University of Applied Sciences DEQARINST0584 DE0302 Hochschule Osnabrück (FH) Osnabrück (Germany)
- Ostbayerische Technische Hochschule Amberg-Weiden DEQARINST0516 DE0221 Amberg (Germany)
- Ostbayerische Technische Hochschule Regensburg DEQARINST0529 DE0234 Regensburg (Germany)
- Ostfalia University of Applied Sciences DEQARINST0581 DE0298 Ostfalia Hochschule für angewandte Wissenschaften Wolfenbüttel (Germany)
- Ostim Technical University DEQARINST7662 TR0225 Ostim Teknik Üniversitesi Ankara (Türkiye)
- Ostwestfalen-Lippe University of Applied Sciences DEQARINST0598 DE0316 Hochschule Ostewestfalen-Lippe Lemgo (Germany)
- Otto von Guericke University of Magdeburg DEQARINST0413 DE0103 Otto-von-Guericke-Universität Magdeburg Magdeburg (Germany)
- Oulu University of Applied Sciences DEQARINST0876 FI0471 Oulun ammattikorkeakoulu Oulu (Finland)
- Oxford Centre for Religion and Public Life DEQARINST8643 Oxford (United Kingdom (England))