Professor Wesselingh took up the position of the Chief Executive Officer at the National Health and Medical Research Council (NHMRC) in August 2023.

Professor Wesselingh is an infectious diseases physician and researcher. He undertook his undergraduate and doctoral training at Flinders University and his post-doctoral training at Johns Hopkins in the United States.

Until July 2023, Professor Wesselingh was the inaugural Executive Director of the South Australian Health and Medical Research Institute (SAHMRI). He was also a member of NHMRC Council, Chair of Research Committee, and the President of the Australian Academy of Health and Medical Sciences (AAHMS).

Between 2007-2011, he was Dean of the Faculty of Medicine, Nursing and Health Sciences at Monash University.