[3] The town is in the southeastern part of the county, in the Adirondack Region of New York.

The town was used to relocate former slaves, in part the work of Gerrit Smith, an abolitionist, and in part the result of Civil War veterans inviting freed slaves to return home with them.

The Loon Lake Mountain Fire Observation Station was listed on the National Register of Historic Places in 2008.

[3] The Saranac River, a tributary of Lake Champlain, flows through the southeastern corner of the town.

New York State Route 3 runs diagonally from southwest to northeast across Franklin.

26.0% of all households were made up of individuals, and 11.0% had someone living alone who was 65 years of age or older.