Northumberland County, Pennsylvania
Northumberland County Courthouse in Sunbury
Location within the U.S. state of Pennsylvania
Pennsylvania's location within the U.S.
|Founded||March 21, 1772|
|• Total||478 sq mi (1,240 km2)|
|• Land||458 sq mi (1,190 km2)|
|• Water||19 sq mi (50 km2) 4.0%%|
| • Estimate |
|• Density||204/sq mi (79/km2)|
|Time zone||UTC−5 (Eastern)|
|• Summer (DST)||UTC−4 (EDT)|
|Congressional districts||9th, 12th|
Northumberland County is a county in the U.S. state of Pennsylvania. As of the 2010 census, the population was 94,528. Its county seat is Sunbury. The county was created on March 21, 1772 from parts of Lancaster, Berks, Bedford, Cumberland, and Northampton counties and is named after the English county of Northumberland.