Ontario area codes

Ontario is Canada's most populous province (roughly 15–16 million people) and uses the largest set of area codes in the country. Toronto sits on a five-code overlay complex (416/437/647/942, with 387 reserved for future relief), and every Ontario code except 807 is part of an overlay.

Major metro areas

All Ontario area codes

Every code opens its profile — codes with a full write-up show their place; the rest show live numbering data while their detailed profile is added.

From the CNA (Canadian Numbering Administrator) relief history. 942 is the newest (April 2025). 387 is reserved for future Toronto relief and is not yet in service, so it is excluded.