State Premier Daniel Andrews announced the measures after the highly transmissible strain of COVID-19 linked to Britain infected 13 people in Melbourne.
Australian Open tournament director Craig Tiley said the tournament would continue with crowds for the rest of Friday but fans would be excluded from Saturday (February 13).
The players will enter a biosecure "bubble" from Saturday morning similar to ones that have operated at tournaments around the world for much of the last 12 months. Fans who had already bought tickets will get a refund and Friday's night session would still be
open, despite Andrews encouraging all Victorians to stay at home.