

Sewickley has four land borders with Edgeworth to the northwest, Glen Osborne to the southwest, Sewickley Heights to the northeast, and Aleppo Township to the east. Census Bureau, the borough has a total area of 1.1 square miles (2.8 km 2), of which 1.0 square mile (2.6 km 2) is land and 0.1 square miles (0.26 km 2) (11.11%) is water. Ohio River Boulevard, later designated a part of Pennsylvania Route 65, was completed in 1934. In 1911, the Sewickley Bridge was completed, bringing an end to the ferry industry. The borough was incorporated as simply Sewickley on July 6, 1853, after growth continued as the Pittsburgh, Fort Wayne and Chicago Railway was built through the area. Becoming a small center for education, by 1840 the community was formally established as Sewickleyville. The following year, Sewickley Academy was founded.

In 1837, the Edgeworth Female Seminary was moved from Pittsburgh to what was then called Sewickley Bottom. After the Battle of Fallen Timbers in 1794, settlers began to trickle in to the area, with flatboats, keelboats, and steamboats forming an industry along the Ohio River. The valley surrounding the Big Sewickley Creek was surveyed in 1785 and sold to American Revolutionary War veterans.

Some locals alternatively consider Sewickley to be a Native American word meaning "sweet water." History Old Sewickley Train Station (1887) Contemporary accounts from noted anthropologist Frederick Webb Hodge and the Sewickley Presbyterian Church, as well as the current Sewickley Valley Historical Society concur to varying degrees with Hanna's etymology. According to Hanna, the Asswikale branch of the Shawnee probably borrowed their name from the neighboring Sawokli Muscogee before the former's migration from present-day South Carolina to Pennsylvania. Hanna suggested "Sewickley" came from Creek words for "raccoon" (sawi) and "town" (ukli). The Sewickley Bridge crosses the Ohio River from Sewickley to Moon Township. The population was 3,907 at the 2020 census. It is a residential suburb of the Pittsburgh metropolitan area. Sewickley is a borough in Allegheny County, Pennsylvania, United States, 12 miles (19 km) west northwest of Pittsburgh along the Ohio River.
