The new total is 405 more than Wednesday's case count, the previous record for the province.
The last time the province reported 56 COVID-19-related deaths was on May 12.
Health Minister Christine Elliott said there are 888 new cases in Toronto, 431 in Peel Region, and 418 in York Region.
She also said that there are 257 new cases in Windsor-Essex County and 194 in Ottawa.
Elliott said nearly 63,900 tests have been completed since the last daily update.
There have been a total of 192,159 infections of the novel coronavirus in Ontario, 156,012 resolved cases, and 4,530 deaths.
Ontario will not release new data on Friday but will have two days' worth of updates on Saturday.
Also, a hospital in London, Ont., declared itself free of COVID-19 outbreaks after 23 deaths and more than 150 infections. London Health Sciences Center said University Hospital is outbreak-free as of Dec. 30.