Gloucester County is a county located in the U.S. state of New Jersey. As of the 2000 Census, the population was 254,673. Its county seat is Woodbury. This county is part of the Delaware Valley area. It is located south of Philadelphia and northwest of Atlantic City. According to the U.S. Census Bureau, the county has a total area of 873 km˛ (337 mi˛). 841 km˛ (325 mi˛) of it is land and 32 km˛ (12 mi˛) of it (3.62%) is water.
Gloucester County is largely composed of low-lying river and coastal plain. The highest elevation in the county is a slight rise along County Route 654 southeast of Cross Keys that reaches approximately 180 feet (55 m) above sea level; the lowest point is sea level at the Delaware River.

As of the census˛ of 2000, there were 254,673 people, 90,717 households, and 67,221 families residing in the county. The population density was 303/km˛ (784/mi˛). There were 95,054 housing units at an average density of 113/km˛ (293/mi˛). The racial makeup of the county was 87.07% White, 9.06% Black or African American, 0.19% Native American, 1.49% Asian, 0.03% Pacific Islander, 0.85% from other races, and 1.30% from two or more races. 2.58% of the population were Hispanic or Latino of any race.