Ontario reported 587 new cases of COVID-19 on Thursday, an increase of 476 cases a day earlier.
Another five people have died due to the virus, bringing the provincial death toll to 9,776.
The province conducted 37,057 tests in the last 24 hours with a positivity rate of 1.7 percent.
Of the total new cases, 423 are in individuals who have not been fully vaccinated or have unknown immunization status, while 164 are fully vaccinated.
As per the latest figures, 279 people are hospitalized with COVID-19 (excluding ICU) and 149 are in ICU.
Of the 279 hospitalized patients, 229 were not fully vaccinated or had unknown immunization status and 50 were fully vaccinated. And of the 149 patients in the ICU, 134 are not fully vaccinated or have unknown immunization status and 15 are fully vaccinated.
The province reported 121 new cases related to the school and most of them are students. So far, 780 schools across the province have at least one active case of the virus, and eight schools have been closed.
More than 86 percent of Ontarians aged 12 and older have received a single dose of a COVID-19 vaccine, and more than 81 percent have been fully vaccinated.