Apache Junction is a city in Pinal and Maricopa counties, Arizona, United States. As of the 2020 census, the population was 38,499, most of whom lived in Pinal County. It is named for the junction of the Apache Trail and the Old West Highway. The area where Apache Junction is located used to be known as Youngberg. Superstition Mountain, the westernmost peak of the Superstition Mountains, is to the east.