This is a list of area codes in the province of Ontario: * 226: London, Kitchener–Waterloo, Windsor, and most of Southwestern Ontario; overlays with 519 and 548 * 249: Most of Northeastern and Central Ontario; overlays 705 * 289: Niagara Region, Hamilton, Halton Region, Peel Region, York Region and Durham Region; overlays with 905 and 365 * 343: Ottawa and surrounding Eastern Ontario; overlays with 613 * 365: Niagara Region, Hamilton, Halton Region, Peel Region, York Region and Durham Region; overlays with 905 and 289 * 416: Toronto; overlays with 647 and 437 * 437: Toronto; overlays with 647 and 416 * 519: London, Kitchener–Waterloo, Windsor, and most of Southwestern Ontario; overlays with 226 and 548 * 548: London, Kitchener–Waterloo, Windsor, and most of Southwestern Ontario; o