It comes after the Victorian government accepted changes to gatherings introduced at Sunday night's national cabinet meeting.
Prime minister Scott Morrison announced public gatherings would be limited to two people, unless members were from the same house hold.
These gatherings exclude workplaces and schools.
While the moves have been referred to by some as radical, Victorian premier Daniel Andrews said they were necessary.
“No gathering with friends is worth someone's life,” Mr Andrews said.
“This is not just about grandma, this is about all of us. And unless you want to be burying an elderly relative or your best mate or your parents … then do the right thing.”
New South Wales will also begin enforcing the the lockdown restrictions, with premier Gladys Berejiklian saying the state was in a real position to slow the infection rate.
“We are now in a position now that allows us to control the spread as much as possible,” Ms Berejiklian said.
The new measures came into affect at midnight on Tuesday morning.