Sudbury, formally known as Greater Sudbury, is a city in Canada's Ontario Province. As of a 2006 estimate, the city had a population of 157,857 people. In 2001, the areas in the regional municipality of Sudbury were amalgamated into the city of Greater Sudbury. The city is the largest one in the Northern Ontario area and it belongs to the 24th largest metropolitan area in Canada. By land area, Sudbury, is the largest city in Ontario and is the 7th largest municipality in Canada.

It is one of the 5 cities in the Ontario Province that constitute their own census divisions and are not part of any district, regional municipality or county. The others are Ottawa, Toronto, Hamilton, and Kawartha Lakes. The city is also the only one in Ontario that has two official names. It is called Greater Sudbury in English and is called Grand Sudbury in French.

The area is served by several highways and by the Greater Sudbury Airport.