Born in Glasgow, Scotland, Macdonald was educated in Edinburgh, the University of London (MB, BS) and King's College Hospital.
During this time, he was involved with the Royal College of General Practitioners (MRCGP) and joined the Royal College of Obstetricians and Gynaecologists, obtaining a Diploma in Anaesthetics (DA) and a Diploma in Obstetrics (DRCOG).
In 2000 Macdonald founded and is the current President of Australian Doctors International, which provides non-government health care and development aid in remote and rural regions of Papua New Guinea.
[3] Macdonald resumed his local political career in 2004 when he was elected as Mayor of Manly, serving until 2008.
[4] In the 2011 Queen's Birthday Honours, Macdonald was presented with the Medal of the Order of Australia (OAM) "For service to local government, and to medicine.