The town consisted of a 36-square-mile area that was originally covered with heavy timber, which was mostly hardwoods such as hickory, walnut, and butternut.

Most of the town's drainage was delivered by the Root River and there was an abundance of wildlife including bears, deer, and wolves.

In 1956, town officials were concerned by the possibility that the city of Milwaukee might attempt to annex portions of Franklin.

[6] It is bounded by the city of Oak Creek to the east, the villages of Greendale and Hales Corners and the city of Greenfield to the north, the county of Racine to the south, and the county of Waukesha to the west.

[8] The Root River runs south through Franklin, bisecting the city.

The Common Council is composed of the mayor and six members representing the six aldermanic districts, serving three-year overlapping terms.

The mayor oversees the police and fire departments; nominates the appointment of certain city employees, board and commission members to the council; and is chairman of the Plan Commission and the Community Development Authority.

The city falls within Wisconsin's 1st congressional district, which is represented by Bryan Steil (R).

City government exercises no fiscal control over the school district.

The Oak Creek-Franklin School District serves residents of the far eastern side of Franklin, along 27th street.

The Whitnall School District, which serves primarily the neighboring village of Hales Corners and parts of the city of Greenfield, serves Franklin residents residing on the city's far northwest side.

Franklin's private schools include St. Pauls Lutheran K4–8, founded in 1865 by a group of German Lutherans, and Indian Community School of Milwaukee K4–8, serving Indian children and youth.

Franklin is four miles (6.4 km) from Milwaukee Mitchell International Airport and close to Interstate 94.

Franklin is home to one of the Environmental Protection Agency's Superfund sites.

The site was placed on the National Priorities List in 1986, with remedial action (RA) completed in 1994.

It is bordered on the north by a Hobby Lobby, a tributary that flows into the Root River, and South 27th Street.

The southern boundary of the site is lined with a Goodwill Industries retail store.

As of March 2021, a portion of the site is being considered for development as a dog park.