Victorian Premier Daniel Andrews has tested positive to COVID-19.
The Premier released a statement on Monday saying he had received his results on a rapid antigen test and had "mild symptoms", including a sore throat and temperature.
Mr Andrews said he would now isolate for seven days.
"So far, Cath and the kids have tested negative. As they are close contacts, they will also isolate for the next seven days," he said.
Deputy Premier James Merlino will step in as Acting Premier until at least next Monday.
On Thursday evening Mr Andrews and his family attended the premiere of the musical Hamilton at Her Majesty's Theatre in Melbourne.
The positive result means Mr Andrews will miss the memorial service for Shane Warne being held at the MCG this Wednesday evening.
In late December, the Premier posted on social media about receiving his third COVID-19 vaccine dose.
Opposition Leader Matthew Guy said despite his political disagreements with the Premier, it was his "sincere hope" Mr Andrews and his family were fine.
"I hope he comes through OK, I hope his family are OK and I send my best wishes sincerely and personally to him like any Victorian with COVID," he said.
Victoria reported 8,739 new COVID cases on Monday, but no new deaths.
There are 252 people in hospital in the state, and 56,997 active cases.
