Wilmington Township Mercer County was formed in 1846 and is located at the South end of Mercer County bordering on the Borough of New Wilmington in Lawrence County. Currently, the Township has a population of 1420 as of the last U.S. Census. Assessed valuation of the land within the Township is $15,356,150 with millage set at 4.67. This allows for a value of $71,713 in property taxes for the township annually. An additional millage of .80 has been set for fire protection.

Wilmington Township has 17.3 miles of road that are maintained by all part-time staff. A small area bordering the Borough of New Wilmington is serviced with public water and sewers.

The Township is mainly an agricultural community with a small portion zoned Industrial/Business and Multifamily Residential. Throughout the Township, horse drawn buggies can be found sharing the roadways with vehicles. Part of Wilmington Township's charm is the simple life of the Amish community. The beauty throughout the township can be seen in its farms, small streams, and countryside views.

The Wilmington Township Board of Supervisors meets the second Wednesday each month at 7:00 p.m. at the township building.