Of the new cases, 30 have been linked to known outbreaks -- while 135 remain under investigation, the department said.
The announcement came just hours after Melbourne, Australia's second-largest city and the state capital, went into lockdown. The state border with neighbouring New South Wales has also been shut to stop the virus from spreading further.
Victoria has had 3,098 Covid-19 cases with 22 related deaths since the pandemic began.
New South Wales recorded 13 new cases on Wednesday, the state's Premier Gladys Berejiklian said Thursday.