The eastern half of Union Township occupies the hilltops and western slope of Chestnut Ridge, with the highest elevation of 2,670 feet (810 m) located near the southeast corner of the township, just north of the Summit Hotel. The Mon–Fayette Expressway interchanges with US 119 in the Oliver part of the township, just north of Uniontown the expressway leads northwest to Centerville and southwest to Morgantown. Route 40, the National Road, forms the southwest border of the township, except where the highway passes through Uniontown US 40 leads southeast to Cumberland, Maryland, and northwest to Washington.

Route 119 crosses the northern part of the township, leading northeast to Connellsville and southwest to Morgantown, West Virginia. It is bordered to the southwest by the city of Uniontown, the county seat. North Union Township is in the center of Fayette County. The Oak Hill Estate, Springer Farm, and Summit Hotel are listed on the National Register of Historic Places. A portion of Franklin Township was added to North Union in 1872.

In 1851 Union Township was split along the National Road into North Union and South Union townships. The borough of Uniontown was taken from it in 1796, and a part of Wharton Township was added to it in 1802. Union Township was created in 1783, one of Fayette County's original townships. North Union Township was formed from Union Township in 1851. Unincorporated communities within the township include Oliver, Phillips, Lemont Furnace, Mount Braddock, Jumonville, East Uniontown, Coolspring, West Leisenring, Bethelboro, Youngstown, Percy, Mount Independence, Morgan, Evans Manor, and part of Hopwood. The Laurel Highlands School District serves the township.

The population was 11,826 at the 2020 census, a decline from the figure of 12,728 tabulated in 2010. North Union Township is a township in Fayette County, Pennsylvania, United States.

North union township