The decision comes as Victoria recorded another significant rise in COVID-19 cases in a 24-hour period, reporting 429 new cases and 13 deaths on Monday.
Mitchell Shire had 26 active cases on Monday. Postcode data released on Friday showed most cases were in the south of the shire.
The 3753, 3756 and 3764 postcodes, which includes Wallan, Beveridge and Kilmore, had 18 active cases.
The 3758 postcode, which includes Wandong and Heathcote Junction, had two active cases.
The 3658 and 3659 postcodes, which include Broadford and Tallarook, had two active cases.
Postcodes for Seymour, Puckapunyal and Yea had no active cases. Strathbogie Shire also had no active cases.
Under stage three restrictions there are only four reasons to leave home: shopping for food and supplies, care and caregiving, exercise, and work or study — if it can’t be done from home.
Cafes and restaurants will be forced back to takeaway and delivery only, and gyms will also close.
Schools will go back to remote learning as of Wednesday — including VCE and VCAL students — after a normal day on Monday and a pupil-free day on Tuesday.
School will resume for vulnerable students and children of permitted workers, and specialist schools in regional Victoria will remain open.
Education Minister James Merlino said there would be no change to VCE and VCAL assessments, other than the GAT, and assured finishing students they would get their ATAR before the end of the year.
Childcare and kindergarten services can stay open for all children.
No visitors will be allowed in the home, but regional Victorians are still allowed to visit their intimate partners, even if they live in metropolitan Melbourne.
If you are exercising outdoors, you may do so alone or with one other person, or members of your household.
Metropolitan Melbourne went under stage four restrictions on Sunday, which includes an 8 pm to 5 am curfew, the limit of movement to 5 km from a person’s home, and further industry shutdowns.
Abattoirs across the state will reduce to two-thirds production, as ‘‘non-essential’’ businesses were shut down in metropolitan Melbourne under stage four restrictions.
People living in Melbourne are able to travel to regional Victoria for essential work if they did not have COVID-19 symptoms.
Businesses in regional Victoria can apply for a $5000 grant, while those in Melbourne and Mitchell Shire can apply for up to $10,000 in recognition of spending longer under restrictions.
The Federal Government also announced workers diagnosed with COVID-19 were able to access a $1500 payment if they had run out of sick leave.
Victoria entered a State of Disaster at 6 pm Sunday.
Premier Daniel Andrews said the new restrictions across Victoria would be in place for at least six weeks, until mid-September.