The teen singing sensation came under attack last night during a performance in front of thousands of screaming fans at the the city's Acer Arena.
Justin, 17, was stage singing when someone tossed six eggs from the crowd.
Footage of the incident showed two eggs landing within a metre of the Canadian superstar.
Then four more eggs appeared to fall from directly above the singer, prompting some internet users to question if the incident was all a set-up.
According Australia's Herald Sun, Justin didn't miss a beat during the egg incident.
He continued performing as a helper quickly cleaned up the mess.
The egg attack outraged many Biebers fans who quickly took to the internet.
One web user named Taylor wrote on Thejustinbiebershrine.com: 'I was soo angry when I saw this, I hate whoever did this. Why bother?'
Another fan took to Twitter a warning: 'Dear person who threw eggs at @justinbieber in Sydney, you now have over #9millionbeliebers after you, be afraid! We go harder than hard!'
Skynews Australia posted a short video of the incident on Youtube a short time after it happened.
dailymail.co.uk