According to the U.S. Census Bureau, the township has a total area of 13.2 square miles (34 km2), all land.

The township abuts Maryland on its southern border, near the Fair Hill equestrian trails and grounds.

The southernmost part of the township was originally disputed territory between Pennsylvania and Maryland, resolved eventually by the Mason–Dixon line.

The township was so named in honor of Benjamin Franklin, who had owned land in the area.

Franklin Township is administered by a five-member Board of Supervisors, each of whom serve overlapping six-year terms.

[11] As of April 12, 2024: Like most of Chester County, Franklin Township was a Republican Party stronghold throughout the 20th century but has trended Democratic in recent years.

[12] At the 2020 United States Presidential Election, it voted for a Democratic nominee for president for the first time since 1948.