Heidelberg is a borough located southwest of Pittsburgh in Allegheny County, Pennsylvania, United States. The population was 1,244 at the 2010 census. The borough was named after Heidelberg in Germany, the native home of a large share of the early settlers.
Heidelberg is located at 40°23′27″N 80°5′26″W (40.390919, −80.090693).
According to the United States Census Bureau, the borough has a total area of 0.3 square miles (0.78 km2), all of it land.
Heidelberg has a rich amateur soccer history. Amateur soccer teams from Heidelberg Borough were nationally competitive from the 1920s through the 1950s, winning the amateur national title in 1927, 1929 and 1955.
Heidelberg is mostly bordered by Scott Township; its only other border is with Collier Township to the west
As of the census of 2000, there were 1,225 people, 571 households, and 331 families residing in the borough. The population density was 4,654.3 people per square mile (1,819.1/km²). There were 606 housing units at an average density of 2,302.5 per square mile (899.9/km²). The racial makeup of the borough was 97.63% White, 0.98% African American, 0.24% Asian, 0.24% from other races, and 0.90% from two or more races. Hispanic or Latino of any race were 0.57% of the population.
There were 571 households, out of which 21.0% had children under the age of 18 living with them, 42.6% were married couples living together, 12.1% had a female householder with no husband present, and 42.0% were non-families.