Forbes Avenue is one of the longest streets in Pittsburgh, Pennsylvania, United States. It has a length of about ten miles (16 km) and is named for John Forbes (1707–1759), whose expedition recaptured Fort Duquesne and who renamed the place Pittsburgh in 1758.
The westernmost terminus of Forbes Avenue lies at Stanwix Street in the downtown part of the city, then runs eastward past PPG Place, directly through Market Square and then between the Courthouse and the City-County Building, past Duquesne University, through Uptown, and Oakland where it passes the University of Pittsburgh's Cathedral of Learning and the Carnegie Library of Pittsburgh. From Oakland, Forbes Avenue continues eastward past Carnegie Mellon University and Schenley Park, through the neighborhood of Squirrel Hill, and past Homewood Cemetery and Frick Park before it reaches its eastern terminus at Wilkinsburg.
Allegheny County Courthouse, built in 1884, bounded by Forbes and Fifth Avenues, as well as Grant and Ross Streets.
The Carnegie Institute and Library complex (which houses the Carnegie Museum of Natural History, Carnegie Museum of Art, Carnegie Music Hall, and the main branch of the Carnegie Library of Pittsburgh), built in 1896, at 4400 Forbes Avenue.