Hanover is a borough in York County, Pennsylvania, 19 miles (31 km) southwest of York and 54 miles (87 km) north-northwest of Baltimore, Maryland and is 5 miles (8.0 km) north of the Mason-Dixon line. The town is situated in a productive agricultural region. The population was 15,289 at the 2010 census. The borough is served by the 717 area code and the ZIP Codes of 17331-34. Hanover is named after the German city of Hannover.