Butler is a city and the county seat of Butler County, Pennsylvania, United States. It is located 35 miles (56 km) north of Pittsburgh and part of the Greater Pittsburgh Region. As of the 2010 census, the city population was 13,757.
Butler was named for Maj. Gen. Richard Butler, who fell at the Battle of the Wabash, also known as St. Clair's Defeat, in western Ohio in 1791.
In 1803 John and Samuel Cunningham became the first settlers in the village of Butler. After settling in Butler, the two brothers laid out the community by drawing up plots of land for more incoming settlers. By 1817, the community was incorporated into a borough. The first settlers were of Irish or Scottish descent and were driving westward from Connecticut.