The top men's tennis player was deported after losing a visa battle that centred on the fact he is unvaccinated.
Supporters gathered at the airport in Belgrade, waving the national flag and chanting "we love Novak".
"This is a shame what they did to Novak in Australia," one supporter said. "This is a shame what the world has come to."
"I myself am vaccinated, double-jabbed, but I think no-one should be forced to do something... he was judged and sentenced for his freedom of choice," he added.