The hearing was to begin at 10am in Melbourne (noon NZ time) in the Federal Circuit and Family Court of Australia.
The Age newspaper reported a small, “jovial’’ crowd of around 50 Djokovic supporters gathered outside the court on Monday morning in support of the Serbian star.
The 34-year-old's lawyers will argue that he met the criteria for a temporary exemption under Australian Technical Advisory Group on Immunisation (ATAGI) guidelines and that he was denied procedural fairness during the decision to revoke his visa.
Nicholas Wood, SC, is representing Djokovic with barrister Christopher Tran appearing for the government.
Djokovic, who was expected to be present to the hearing virtually, could be cross-examined by both the judge and the government's barrister.
How he responds will be crucial after documents were released by the Federal Court on Saturday, showing the Serb contracted Covid-19 on December 16 and was free of symptoms before he arrived in Australia.
Eyebrows were raised when pictures then surfaced of Djokovic attending public events, indoors, unmasked and with children in the days that followed his positive test confirmation.
A leaked TA document to players also indicated the deadline for medical exemption applications was December 10, meaning Djokovic's ensuing positive test appeared to be his only avenue to a last-minute green light.
A vocal opponent of vaccine mandates, Djokovic had previously declined to reveal his vaccination status or reason for seeking a medical exemption for sidestepping Australia's vaccine rules.