Apollo is a borough in Armstrong County, Pennsylvania, United States, 35 miles (56 km) northeast of Pittsburgh in a former coal-mining region. Apollo was settled in 1790, laid out in 1816, and incorporated as a borough in 1848. The population was 1,647 at the 2010 census.
The area was sectioned in 1769, following the Treaty of Fort Stanwix, as a farm known as "Warren's Sleeping Place", named after a Native American trader from the area named Edward Warren. It was soon surveyed and divided into lots, with the town of Warren officially being added to the Greensburg register on 9 November 1816. The log cabin home of the Drake family still stands in the area, and is one of the oldest buildings in Armstrong County.
With the introduction of the post office, the area was officially renamed from Warren to Apollo in 1848 to avoid confusion with the post office of another town in Pennsylvania of the same name. The present name is after Apollo, the Greek and Roman god of music, healing, light, prophecy and enlightenment.
By the late 19th century the Apollo Iron & Steel Company dominated the local economy. In 1895, the company's president, George Gibson McMurtry, hired famous landscape architect Frederick Law Olmsted to design a town for Apollo Iron & Steel's workers. The result was the neighboring town of Vandergrift. In 1911, Apollo became home to the first public library in Armstrong County.