Premier Doug Ford has ordered the closure of all non-essential businesses in Niagara and across the rest of the province.
He says it will come into effort after midnight Tuesday night.
His government will release a list of what will be allowed to stay open tomorrow.
Ford says food will remain on grocery store shelves and people will still be able to access medication.
Ontario reported another 78 cases of COVID-19 this morning, which brings the province-wide total to over 500.