| O | Oral & Maxillofacial Surgery, Queen Mary Hospital | Others | |
| J | Oral and Maxillofacial Surgery services | | |
| O | Oral and Maxillofacial Surgery, License Examination of The Dental Council of Hong Kong | Others | |
| O | Oral Diseases | Others | |
| O | Oral Health Unit, Cochrane Collaboration, Journal of Dentistry | Others | |
| O | Oral History Project, Central and Western District Council | Others | |
| O | Oral Proficiency Assessment for Working Professionals Committee, NIE, NTU, Singapore | Others | |
| P | Orbis | | |
| O | ORCID Membership and Fees Committee | Others | |
| O | Organising Committee | Others | |
| O | Organising Committee HKIDEAS | Others | |
| O | Organising Committee of Asian Physics Olympiad 2016 | Others | |
| O | Organising Committee of HOPE (Harbourfront planning Out of Public Engagement) Summit, Harbourfront Enhancement Committee, Hong Kong | Others | |
| O | Organising Committee, 17th APCChE 23-27 Aug 2017, Hong Kong | Others | |
| J | Organization Committee | | |
| O | Organization Committee, Asia-Pacific Conference on Vision, 2011 | Others | |
| J | Organizing Committee | | |
| O | Organizing Committee | Others | |
| O | Organizing Committee for HKGS Annual Scientific Meeting | Others | |
| O | Organizing Committee for International Council on Education for Teaching Global Assembly 2004 | Others | |
