[14] Gloucester County borders Philadelphia, the nation's sixth-most populous city, to its northwest across the Delaware River.

[16] National Park in Gloucester County was the site of the American Revolutionary War's Battle of Red Bank, where Fort Mercer once stood.

The remains of the Royal Navy's HMS Augusta were laid in Red Bank Battlefield Park until they were later moved to Gloucester City.

During the colonial era, Gloucester County's main industry sector was agriculture.

[18] Average temperatures in the county seat of Woodbury have ranged from a low of 26 °F (−3 °C) in January to a high of 87 °F (31 °C) in July.

[20] Swedesboro and Bridgeport were among the earliest European settlements in New Jersey and were both part of the 17th century New Sweden colony.

On May 17, 1694, the county was officially formed and its boundaries defined as part of West Jersey.

[6] The Bureau of Economic Analysis calculated that the county's gross domestic product was $14.0 billion in 2021, which was ranked 14th in the state and was a 2.8% increase from the prior year.

The Commodore Barry Bridge crosses the Delaware River, carrying U.S. Route 322 between Chester, Pennsylvania and Logan Township in the county.

The Atlantic City Expressway briefly passes through the county in Washington Township before ending at an interchange with Route 42.

Additional public transportation in the county includes the 400, 401 (from Salem), 402 (from Pennsville Township), 403, 408, 410 (from Bridgeton), and 412 (from Sewell) routes, and local service is available on the 455 (Cherry Hill to Paulsboro) and 463 (between Woodbury and the Avandale Park/Ride in Winslow Township) routes.

SMS Rail Lines handles interchanges with CSX Transportation and Norfolk Southern Railway.

[50] As of 2025[update], Gloucester County's Commissioners are (with terms for director and deputy director ending December 31): Pursuant to Article VII Section II of the Constitution of New Jersey, each county in New Jersey is required to have three elected administrative officials known as constitutional officers.

[70][71] For the 119th United States Congress, New Jersey's 1st congressional district is represented by Donald Norcross (D, Camden).

[72][73] For the 119th United States Congress, New Jersey's 2nd congressional district is represented by Jeff Van Drew (R, Dennis Township).

Dave Bailey (D) Cody Miller (D) Bill Moen (D) The county has tended to be a bellwether, as it has voted for the national winner all but four times since 1936.

[79] GCEMS was launched in September 2007 with the goal of providing emergency medical services to county residents within nine minutes from the time of dispatch 90 percent of the time, which is considered to be the gold standard in EMS services.

GCEMS administrative offices are located at the county's Emergency Response Center in Clayton.

[81] Gloucester County's special weapons and tactics (SWAT) unit includes police officers from Gloucester County and provides emergency services for SWAT-oriented scenarios, including barricaded and suicidal subjects, hostage rescues, high-risk warrant service, dignitary protection, and counterterrorism responses.

[83] The Gloucester County Historical Society, founded in 1903, maintains a collection of materials and artifacts related to the history of South Jersey.