Originally part of Versailles Township, it is named for Robert Pitcairn, a former superintendent of the Pittsburgh division of the Pennsylvania Railroad.

Robert Pitcairn was instrumental in locating switching yards, an engine roundhouse and car repair shops in the area in the 1880s near what was known as Wall Station.

Lots were planned to accommodate railroad workers in a town known as Walurba , meaning a suburb of Wall.

In 1893, residents decided they wanted to form their own community, separate from what were then Patton Township and Wall. The petition was approved the following year and in 1897 Walurba Station was changed to Pitcairn.

The depot is now a municipal parking lot and the railroad yards are gone.

Pitcairn has the distinction of being the only municipality in Allegheny County to provide its own electric and cable television service. In 1936 and 1937, at the height of the Great Depression, the municipality sent residents an electric bill marked "Paid in Full" as a Christmas present.

The borough still redistributes electricity to its residents and provides its own cable television service.