Ontario reported 578 patients in intensive care with COVID-19 on Monday and 3,887 patients hospitalized with the virus.
That's up from 3,595 people in hospital with the virus the previous day, and down from 579 patients in ICU.
Health Minister Christine Elliott noted that not all hospitals in the province report data from the weekends.
The province reported 8,521 new COVID-19 cases on Monday, though Public Health Ontario has said the number is likely higher because of the current testing policy.
More than half of the province's long-term care homes were reporting active COVID-19 outbreaks as of Monday.
Eighty-two per cent of Ontario residents aged five and older had received both doses of a COVID-19 vaccine and 88 per cent have at least one dose.