Wee Loon Ong graduated from Monash University with BMedSci and MBBS. Following completion of internship at the Alfred Health, he pursued an MPhil in Epidemiology at the University of Cambridge, graduating first with the GSK Prize. He subsequently undertook specialist training in radiation oncology within the Victorian Network, rotating through the Peter MacCallum Cancer Centre, Ballarat Regional Integrated Cancer Centre, and Olivia Newton-John Cancer Centre. He is currently a Radiation Oncology Clinical Research Fellow at Olivia Newton-John Cancer Centre, and is concurrently pursuing a Doctorate of Medicine higher research degree through the University of Cambridge as part of the Royal Australia and New Zealand College of Radiologists (RANZCR) Clinician/ Scientist Pathway. He is also an Adjunct Lecturer the Department of Epidemiology and Preventive Medicine, Monash University, and Adjunct Research Fellow at the Health and Biomedical Informatics Centre, University of Melbourne. 

He sits on the RANZCR FRO Radiation Oncology Trainee Committee (ROTC), Quality Improvement Committee (QIC) and Victoria/ Tasmania Training Network (VICTRANET) Network Governance Committee (NGC). He is a member of the European Society of Radiotherapy and Oncology (ESTRO), Australian and New Zealand Urogenital and Prostate Trial Group (ANZUP), Australasian Gastro-Intestinal Trial Group (AGITG), Cooperative Trials Group for Neuro-Oncology (COGNO), and Health Services Research Association of Australia and New Zealand (HSRAANZ).

His current research interest is primarily in health services and patient-centred outcomes research in cancer. These include research on adoption of evidence-based practice in radiation oncology using administrative healthcare databases, as well as evaluation of the pattern of prostate cancer care in the population-based Prostate Cancer Outcomes Registry Victoria (PCOR-Vic). He was involved in the development of value-based patient-centred standard set of breast cancer outcomes as part of the ICHOM Breast Cancer Working Group. He also has interest in implementation science research, and was awarded the Victorian Cancer Agency Travel Scholarship to attend the US NCI Training Institute in Dissemination and Implementation Research in Cancer (TIDIRC). He has published widely, relative to opportunity, including first author publication in JAMA Oncology.