South New Castle, Pennsylvania

South New Castle, Pennsylvania
Municipal building
Location in Lawrence County, Pennsylvania
Coordinates: 40°58′32″N 80°20′41″W / 40.97556°N 80.34472°W / 40.97556; -80.34472
CountryUnited States
StatePennsylvania
CountyLawrence
Established1901
Area
 • Total
0.32 sq mi (0.84 km2)
 • Land0.32 sq mi (0.84 km2)
 • Water0 sq mi (0.00 km2)
Elevation
(middle of borough)
1,000 ft (300 m)
Highest elevation
(southwest corner of borough)
1,100 ft (340 m)
Lowest elevation
(Big Run)
840 ft (260 m)
Population
 (2020)
 • Total
647
 • Density1,995.7/sq mi (770.53/km2)
Time zoneUTC-4 (EST)
 • Summer (DST)UTC-5 (EDT)
Area code724
FIPS code42-72376

South New Castle is an unincorporated community and former borough in Lawrence County, Pennsylvania, United States. The population was 649 at the 2020 census. It is a residential community south of the city of New Castle.

South New Castle borough was founded in 1901. In 2023, the electorate of Shenango Township and South New Castle voted in resounding favor of the dissolution of the borough into Shenango Township. The official merger took place on January 1, 2026.