Ontario is the most populous and second-largest in area of Canada's ten provinces. It is found in east-central Canada. Its capital is Toronto. Ottawa, the capital of Canada, is also located in Ontario. As of July 1, 2005 there are 12,541,410 Ontarians (residents of Ontario), representing approximately 37.9% of the total Canadian population and an area of 1,076,395 square kilometres (415,598 sq. mi.).

List of Ontario counties
Ontario is bounded on the north by Hudson Bay and James Bay, on the east by Quebec, on the west by Manitoba, and on the south by the U.S. states of Minnesota, Michigan, Ohio, Pennsylvania and New York. Ontario's long American border is formed almost entirely by lakes and rivers, starting in Lake of the Woods and continuing to the Saint Lawrence River near Cornwall; it passes through the four Great Lakes Ontario shares with bordering states, namely Lakes Superior, Huron (which includes Georgian Bay), Erie, and Ontario (for which the province is named; the name Ontario itself is a corruption of the Iroquois word "Onitariio" meaning "beautiful lake" or "Kanadario," variously translated as "beautiful water"). There are approximately 250,000 lakes and over 100,000 kilometres (62,000 mi) of rivers in the province.