Gabriel Leung is the fortieth Dean of Medicine (2013-), inaugural Helen and Francis Zimmern Professor in Population Health and holds the Chair of Public Health Medicine at the University of Hong Kong (HKU). He was the last Head of Community Medicine (2012-3) at the University as well as Hong Kong's first Under Secretary for Food and Health (2008-11) and fifth Director of the Chief Executive's Office (2011-2) in government.

He is an elected member of the US National Academy of Medicine and was awarded the Gold Bauhinia Star (second highest civilian honour) by the Hong Kong government for distinguished service in protecting and promoting population health. 

A specialist in public health medicine, Leung's interdisciplinary work revolves around topics that have major population health impact locally, where Hong Kong is a reliable and unique epidemiologic sentinel for mainland China and the Chinese diaspora, or where the SAR is best placed to address the fundamental science at hand globally.

Leung is one of Asia's leading epidemiologists and global health exponents, having authored more than 500 scholarly papers with an h-index of 66 (Scopus). His research defined the epidemiology of three novel viral epidemics, namely SARS in 2003, influenza A(H7N9) in 2013 and most recently COVID-19. He led Hong Kong government's efforts against pandemic A(H1N1) in 2009. He was founding co-director of HKU's World Health Organization (WHO) Collaborating Centre for Infectious Disease Epidemiology and Control (2014-8) and currently directs the Laboratory of Data Discovery for Health at the Hong Kong Science and Technology Park (2020-).

In parallel, Leung leads several large-scale longitudinal cohorts (Children of 1997, FAMILY, Department of Health Elderly Health Service cohort), tracking tens of thousands of lives to study the fundamental causes of non-communicable conditions and to explain the health impacts of contemporary social phenomena.

A final strand of his work concerns the economics and policy issues of health systems. His team is the government's health accountant and projects health care human resources needs. Regionally, Leung has tirelessly worked to build capacity throughout the Asia Pacific. He served as founding Chair of the Asia Pacific Observatory on Health Systems Policies (2010-14) and continues to lead its Strategic Technical Advisory Committee (2018-).

Leung regularly advises national and international agencies including the World Health Organisation, World Bank, Asian Development Bank, Boao Forum for Asia, Institut Pasteur, Japan Center for International Exchange and China Centers for Disease Control and Prevention. He is an Adjunct Professor of Peking Union Medical College Hospital and Adjunct Professorial Researcher of the China National Health Development Research Center.

Locally, he was Vice President and Censor in Public Health Medicine of the Hong Kong College of Community Medicine (2006-8), and an elected council member of the Hong Kong Academy of Medicine (2012-9). He is a member of the Hospital Authority (2013-) and completed two terms on the University Grants Committee (2014-9), which are respectively a statutory agency responsible for all public health care services and a government advisory body on the development and funding requirements of the higher education sector.

He edited the Journal of Public Health (2007-14), was inaugural co-editor of Epidemics, associate editor of Health Policy and is founding deputy editor-in-chief of China CDC Weekly. He currently serves on the editorial boards of seven journals, including the British Medical Journal.

After reading medicine at the University of Western Ontario, he completed family medicine residency training in Toronto. He earned a master's from Harvard University and research doctorate from HKU.