Nanticoke is a city in Luzerne County, Pennsylvania, United States. As of the 2020 census, the population was 10,628, making it the third largeā¦Nanticoke is a city in Luzerne County, Pennsylvania, United States. As of the 2020 census, the population was 10,628, making it the third largest city in Luzerne County. It occupies 3.6 square miles of land. Nanticoke is part of Northeastern Pennsylvania.