This 175-foot-high domed courthouse rises above the skyline of Greensburg from the site of three previous courthouses. The Beaux-Arts building is constructed of steel and faced with granite. The ground floor is rusticated, geometric terra-cotta ornament adorns the upper floors and dome, arid the roofline has personifications of Justice, Law, and the People. Inside, the dome covers a four-story rotunda enriched with marble mosaics, San Domingo mahogany, and bronze railings along the grand staircase. This ornate interior is the work of decorator Paul Hoffman, with murals by French muralist Maurice Ingres. Pittsburgh artist Carroll Westfall restored the murals. The courthouse was restored and expanded with a six-story addition to the west in 1978 by a Greensburg-based architectural firm. Although lacking classical decoration, the addition's similar granite surfaces and landscaped courtyard blend with the original building.
The courthouse's architect, Pittsburgh's William Kauffman (1857–1945), is often associated with his contemporary Edward M. Butz (1851–1916) in designing large public buildings, including two Pennsylvania courthouses, in Fayette ( FA1) and Clarion ( CL1) counties. They designed buildings together between c. 1882 and c. 1910.