Wee Loon Ong is currently a Clinical Fellow at Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto.

He graduated from Monash University with BMedSci and MBBS in 2010, and completed an MPhil in Epidemiology from the University of Cambridge in 2013, graduating first in class with the GSK prize. He then undertook RANZCR Radiation Oncology specialty training (2016-2021) within the Victorian Training Network (rotating through Peter MacCallum Cancer Centre, Austin Health Olivia Newton-John Cancer Centre, and Ballarat Health), and spent the final year of his training as Prostate Cancer Fellow at the Alfred Health. He concurrently pursued a Doctor of Medicine (MD) research degree through the University of Cambridge as part of the RANZCR Clinician-Scientist Training Pathway.

He is actively involved in RANZCR, as a current member of the Radiation Oncology Research Committee (RORC), and ex-officio member of the Radiation Oncology Education and Training Committee (ROETC). He was previous Chair of the Radiation Oncology Trainee Committee (ROTC), and was trainee representative on the Faculty Council, and Quality Improvement Committee (QIC). He is also a current member of the Trans-Tasman Radiation Oncology Group (TROG) Genitourinary Working Party and CNS Working Party. He is member of American Society of Clinical Oncology (ASCO), American Society of Radiation Oncology (ASTRO), American Brachytherapy Society (ABS), Australasian Brachytherapy Group (ABG), Australian and New Zealand Urogenital and Prostate Trial Groups (ANZUP), and Cooperative Trials Group for Neuro-Oncology (COGNO).

His clinical interests are primarily in prostate cancer (including brachytherapy) and CNS cancer (including stereotactic radiation therapy). His research interests are in health services research using population-based administrative dataset such as the Victorian Radiotherapy Minimum Data Set and clinical quality registry database such as the Prostate Cancer Outcomes Registry. He has published widely, relative to opportunity and stage of career, with more than 50 publications to date, in high impact journals such as JAMA, JAMA Oncology, and European Urology. He has received several competitive grants and research awards during his radiation oncology training, including the Victorian Veski Fellowship and the RANZCR Bourne and Langlands Prize. He is also regular peer reviewer for several oncology journals.