McKees Rocks, also known as "The Rocks", is a borough in Allegheny County in Western Pennsylvania, United States, along the south bank of the Ohio River. Part of the Pittsburgh metropolitan area, its population was 5,920 at the time of the 2020 census.

The borough is within the Sto-Rox School District, which serves McKees Rocks and neighboring Stowe Township. The local high school is Sto-Rox High School.

The Pittsburgh, Allegheny and McKees Rocks Railroad was, and the Pittsburgh and Ohio Central Railroad is, located in an area along the river known as the "Bottoms".

The McKees Rocks Bridge, which carries traffic between McKees Rocks and Pittsburgh, is the longest bridge in Allegheny County, at 7,293 feet (2,223 m). McKees Rocks had one of the largest Indian mounds in the state, built by the Adena and Hopewell peoples a thousand years before Europeans entered the area.

In the past, the city was known for its extensive iron and steel interests. There were large railroad machine shops and manufacturers of locomotives and freight and passenger cars. Other factories produced springs, enamel ware, lumber, wall materials, plaster, nuts and bolts, malleable castings, chains and forgings, tin ware, concrete, and cigars.

McKees Rocks is also known as the birthplace of former Ohio Governor John Kasich and late television salesperson Billy Mays.

For thousands of years, Native Americans inhabited the region. The Adena culture built a large earthwork mound here, which was a burial site. It was augmented in later years by members of the Hopewell culture. This was the largest such mound in the state. The Carnegie Museum of Natural History excavated half the mound in 1896. Its archaeologists traced the construction history and unearthed the remains of 33 people. The mound crowned a high bluff that overlooks Chartiers Creek and the Ohio River. The bluff under the mound was quarried for municipal paving some time after the archaeological dig, eliminating what remained of the Indian burial site. This site was considered by George Washington as a possible location for Fort Pitt, which he eventually ordered built on the site of the destroyed French Fort Duquesne in what is now Pittsburgh's Point State Park.

Around 1749, the French-Canadian explorer Pierre Joseph Celoron de Blainville visited the area and discovered a "written rock" inscribed with markings he believed were made by Native Americans. Celeron named the place after the rock, and it eventually became known as McKees Rocks. Writing in 1918, historian John Boucher stated that the inscriptions had "long since faded away, if indeed they were anything other than marks made by English fur traders."