According to the United States Census Bureau, the township has a total area of 1.6 square miles (4.1 km2), all land.
Originally part of Pitt Township and the Depreciation Lands, reserved for Revolutionary War veterans, it was named after Jonathan Leet,[6] a surveyor who laid out the town of Beaver Falls.
One of the Leet descendants, David Shields, served as Hays' personal aide during the Civil War.
The original boundaries of the township included what are now Edgeworth, Leetsdale and part of Sewickley Heights.
After the Civil War, the residents decided to file a petition to form a separate municipality because they were upset at the level of services they received from Sewickley Township.
The votes were counted at the home of Justice of the Peace John Way Jr., grandson of one of original property owners in the area, Caleb Way, a Quaker.