White Marsh is an unincorporated community and census-designated place in Baltimore County, Maryland, United States. The population was 9,513 at the 2010 census. White Marsh is a northeast suburb of Baltimore.

In 1965, the largely undeveloped northeast corridor was identified by Baltimore County as the preferred site for intensive development. A town center was proposed to be located west of Belair Road at the planned intersection of White Marsh and Walther Boulevards.

The Harry T. Campbell Sons Corporation owned thousands of acres of land to the east of the planned town center, on both sides of Interstate 95. The land was bought in the 1930s and was being mined of its natural sand and gravel deposits. The Campbell family merged its sand and gravel business with an international building supply company. A new family-owned entity was charged with rejuvenating the family's property in northeast Baltimore County, which was covered with deep craters and pits.

In January 1943, the Cowenton Volunteer Fire Company was founded to counter the threat of incendiary bombings from the Axis Powers during the ongoing Second World War. The volunteer fire department, which was renamed the White Marsh Volunteer Fire Company in 2003, currently maintains a fire department and five vehicles, including two fire engines and an ambulance.

In the late 1960s, Nottingham Properties began analyzing the feasibility of a new town in White Marsh. From the first, the intent was to incorporate a variety of land uses and community services, including residential, retail, business, and industrial.

In 1969, a planning analysis of regional growth found development potential in the northeast brought about by the construction of I-95. The county was planning a series of arterial roads traveling in a northeasterly direction from Baltimore County that would pass through the Campbell land. The County agreed to move the planned town center east, to be developed on 1,500 acres (610 ha) of the Campbell land.

The plan was for a town center in an area created by a triangle of arterial roads. A mall would be at the center. The density of residential and business development would decline as it moved away from the mall. A residential sector was designated to the north, between Silver Spring Road and the planned White Marsh Boulevard. It would include all residential densities except high-rise. The area east of the town center to I-95 would be for office and research facilities. The Campbell land east of I-95 was slated for future industrial development.

Rezoning of the area was completed in 1970 and 1971. In 1979 the area was formally designated as a town center in the Baltimore County Master Plan.