Elizabeth is a borough in Allegheny County, Pennsylvania, United States, on the east bank of the Monongahela River, where Pennsylvania Route 51 crosses, 15 miles (24 km) upstream (south) of Pittsburgh and close to the county line.

[4] The borough of Elizabeth is entirely contained within the 15037 USPS ZIP code.

Mayor: Barry Boucher Elizabeth Town was founded in 1787 by Samuel Mackay, Colonel Stephen Bayard and his wife Elizabeth Mackay Bayard (for whom the town was named).

Elizabeth was one of the first seven townships organized by Allegheny County the following year; the others being Moon, St. Clair, Mifflin, Versailles, Plum, and Pitt.

The original Elizabeth Township comprised the entire triangle of land between the Monongahela and Youghiogheny Rivers.

In 1803, the keelboat used for the first stages of the Lewis and Clark Expedition was built in Elizabeth.

Steamboats were built and repaired at O'Neil & Company from as early as 1895, and the Elizabeth Marine Ways operated between at least 1898 to 1925.

The cemetery contains the remains of Elizabeth Mackay Bayard, for whom the town is named.