The warning from Environment Canada, issued just after noon Monday, stretches from north of the Barrie area, south to the London area.
The Greater Toronto Area and the Niagara Region are included in the warning.
Freezing rain was expected this morning, afternoon and potentially evening, according to the forecast. Some snow may be in the mix this morning and light rain should follow the freezing rain.
The warnings extended to the Tweed and Mallorytown areas later in the morning. They had ended for everywhere but Mallorytown by just after 1 p.m.
Tri-Board Student Transportation Services, which handles English school buses in the area, has cancelled buses. The Consortium de transport scolaire d'Ottawa has cancelled buses in Kingston and Trenton.
The Renfrew County Joint Transportation Consortium has cancelled school buses in the Madawaska area only.