Professor Dr. Ong is an English Queen's Counsel; lawyer in Brunei and Singapore; and a visiting law professor at Civil law jurisdictions. He has acted as counsel or arbitrator in over 350 international commercial and investment arbitrations. Dr. Ong is currently Chairman of International Advisory Board of Thailand Arbitration Center (THAC); President of Arbitration Association Brunei Darussalam(AABD); Advisor Governing Council, BANI(Indonesia); Appointing Council, Chinese-European Arbitration Centre (CEAC) (Germany); and Chairman, Advisory Board, (JIIART)(Japan). FCIArb; FMIArb; FSIArb; DiplCArb; Chartered Arbitrator (CIArb) and Chartered Arbitrator (IDRRMI, HK). Advocate & Solicitor of the Supreme Courts of Brunei and Singapore. First ASEAN practitioner lawyer to be elected Master of the Bench of the Inner Temple (2010). First ASEAN national lawyer appointed English Queen's Counsel. He is currently the Chairman of the Regional Arbitral Institutes Forum and a Vice-President of APRAG.