Mechanicsburg is a borough in Cumberland County, Pennsylvania, USA, eight miles (13 km) west of Harrisburg. It is part of the Harrisburg–Carlisle Metropolitan Statistical Area. Mechanicsburg was settled in 1806 and incorporated as a borough on April 12, 1828. It is in a rich agricultural region known as the Cumberland Valley, a broad zone between South Mountain and the ridge-and-valley Appalachians. In 1900, 3,841 people lived here; in 1910, 4,469, which increased to 5,709 in 1940. As of the 2000 census, the borough population was 9,042. Mechanicsburg is home of Jubilee Day, the largest and longest-running one-day street fair on the east coast. It is estimated as many as 60,000 people attend Jubilee Day annually. Mechanicsburg lies in the center of a regional transportation crossroads, with Interstate 81, Interstate 76, Interstate 83, US Route 11, and US Route 15 passing in close proximity to the borough. Additionally, the Appalachian Trail passes through Pennsylvania a few miles from Mechanicsburg, in nearby Boiling Springs.
Mechanicsburg is located at 40°12′44″N 77°00′22″W / 40.212089°N 77.006143°W / 40.212089; -77.006143.
According to the United States Census Bureau, the borough has a total area of 2.6 square miles (6.7 km2), all of it land.