Jeremy Millar trained in Medicine at Otago University, in New Zealand, with a simultaneous research degree in biochemistry studying gene regulation. He commenced specialist training in Wellington and completed this at the Peter MacCallum in Melbourne, Australia.  He held a specialist appointment there before joining the radiation oncology department at the Alfred. He has looked after patients with genito-urinary cancers since that time, establishing and growing the prostate brachytherapy program there. He spent just over two years as part-time Director of the Southern Melbourne Integrated Cancer Service (SMICS) in Melbourne, Director  radiation oncology for ten years, and is currently Research Director, Alfred Health. 

His research interests are mostly around aspects of prostate cancer spanning the range from basic biology, through aspects of clinical care and comparative trials, quality of care, epidemiology and health service research in prostate cancer care. In recent years the focus has been on clinical aspects of prostate brachytherapy, and on cancer quality outcomes registries, especially in prostate cancer. He has published more than a hundred papers in peer-reviewed journals, and has been awarded millions of dollars in research grants.

Jeremy Millar has also had a long-term commitment to the cancer-control community and public health serving in many capacities on the Cancer Council. He was a director on the Cancer Council Australia (CCA) board 2015-2021, CCA deputy chair 2019-2021 and Chair Cancer Council Victoria 2018-2025. He was a member of the Council of the Faculty of Radiation Oncology, Royal Australian College of Radiation Oncology (2018-2024) , and chaired their Quality Improvement Committee (2019-2024). He has been a Non-Executive Director of VicHealth since June 2025.