Allegheny City was a municipality that existed in the U.S. state of Pennsylvania from 1788 until it was annexed by Pittsburgh in 1907. It was located north across the Allegheny River from downtown Pittsburgh, with its southwest border formed by the Ohio River, and is known today as the North Side. The city's waterfront district, along the Allegheny and Ohio rivers, became Pittsburgh's North Shore neighborhood.

The area of Allegheny City included the present Pittsburgh neighborhoods of Allegheny Center, Allegheny West, Brighton Heights, California-Kirkbride, Central Northside, Chateau, East Allegheny, Fineview, Manchester, Marshall-Shadeland, North Shore, Northview Heights, Perry North, Perry South, Spring Garden, Spring Hill–City View, Summer Hill, and Troy Hill.