Map - Greater Sudbury (Greater Sudbury)

Sudbury, officially the City of Greater Sudbury, is the largest city in Northern Ontario by population, with a population of 166,004 at the 2021 Canadian Census. By land area, it is the largest in Ontario and the fifth largest in Canada. It is administratively a single-tier municipality and thus is not part of any district, county, or regional municipality. The City of Greater Sudbury is separate from, but entirely surrounded by the Sudbury District. The city is also referred to as "Grand Sudbury" among Francophones.

The Sudbury region was inhabited by the Ojibwe people of the Algonquin group for thousands of years prior to the founding of Sudbury after the discovery of nickel ore in 1883 during the construction of the transcontinental railway. Greater Sudbury was formed in 2001 by merging the cities and towns of the former Regional Municipality of Sudbury with several previously unincorporated townships. Being located inland, the local climate is extremely seasonal, with average January lows of around -18 C and average July highs of 25 C.

The population resides in an urban core and many smaller communities scattered around 330 lakes and among hills of rock blackened by historical smelting activity. Sudbury was once a major lumber center and a world leader in nickel mining. Mining and related industries dominated the economy for much of the 20th century. The two major mining companies which shaped the history of Sudbury were Inco, now Vale Limited, which employed more than 25% of the population by the 1970s, and Falconbridge, now Glencore. Sudbury has since expanded from its resource-based economy to emerge as the major retail, economic, health, and educational center for Northeastern Ontario. Sudbury is also home to a large Franco-Ontarian population, which influences its arts and culture.

James Worthington, the superintendent of construction on the Northern Ontario segment of the railway, selected the name Sudbury after Sudbury, Suffolk, in England, which was the hometown of his wife Caroline Hitchcock.

The city's official name was changed to Greater Sudbury in 2001, when it was amalgamated with its suburban towns into the current city, on the grounds of ensuring that the merger did not erase the longstanding community identities of the outlying towns. In everyday usage, however, the city is still more commonly referred to as just Sudbury.