With the exception of Chapleau, all of the district's incorporated municipalities are found in the area immediately surrounding the city of Greater Sudbury to the west, east and south.

Because the districts of Northern Ontario are unincorporated territorial divisions, unlike the counties or regional municipalities of Southern Ontario, the city of Greater Sudbury is legally defined as part of the district in the geographic sense.

[1] The Sudbury District is served by Trans-Canada Highways 17, which leads from the community of Walford (Sables-Spanish Rivers) in the west to the community of Warren (Markstay-Warren) in the east, and 69, which enters the district at French River and exits at the southern boundary of Greater Sudbury.

Virtually the entire route of Highway 69 within the Sudbury District is now four-laned as of December 2021, with the completion of the segment between the French River and Grundy Lake Provincial Park, while the route narrows back to a two-lane highway in the Parry Sound District until widening back into Highway 400 at Carling.

The freeway conversion of the remaining route, and its eventual renumbering as an extension of Highway 400, are expected in the future, although no exact date has been confirmed as of 2022 for the completion of the project.