An industrial complex in Farrell, Pennsylvania, United States, seen looking south from Pennsylvania Routes 718/760 north of the Staunton Street intersection. – Nyttend, Public domain – Wikimedia Commons Farrell is located in Mercer County. About 4,258 people live here (as of 2020). Between 2010 and 2020, the population declined from 5,111 to 4,258. There are about 143 streets in Farrell. The region was founded in 1899. The postal codes are 16121. Farrell is city of Pennsylvania. Among other things, Farrell has public Transport, supermarkets and schools. More information at www.cityoffarrell.com.