Delaware Cities by Population 2025

Delaware, though geographically the second-smallest state in the U.S., has a diverse and layered municipal governance system. The state is divided into three counties—New Castle County, Kent County, and Sussex County—and contains 57 incorporated municipalities (cities, towns, and villages), each of which plays a vital role in the state’s administration and service delivery. Delaware’s local governance is characterized by strong municipal governments and the absence of a county-level police force, except for New Castle County.

New Castle County, home to Wilmington, the state’s largest city (population around 70,000), is unique in that it has the state’s only county police department. This department provides law enforcement in unincorporated areas, such as Bear and Middletown, while Wilmington and other incorporated cities manage their own police departments. Wilmington, a center of business and finance, operates under a mayor-council form of government, where the mayor holds executive authority, overseeing public services like the Wilmington Police Department, public works, and economic development initiatives.

In contrast, Kent County and Sussex County do not operate their own police forces, relying instead on the Delaware State Police and local town or city police departments. Smaller towns like Smyrna in Kent County (population around 12,000) or Rehoboth Beach in Sussex County (population 1,200 off-season, ballooning to over 25,000 in summer months) handle localized services like law enforcement and public utilities but depend on county governance for broader services such as land use regulation, road maintenance, and property assessments.

Delaware’s counties manage zoning, development, and certain social services but otherwise leave much of the local governance to individual municipalities. For example, Dover, the state capital (population approximately 40,000), manages its own police force, fire services, and public utilities. Dover operates under a council-manager system, where the city manager handles day-to-day administration.

Delaware has significant unincorporated areas, especially in rural Sussex County. These areas, known for their agricultural landscapes and tourism-driven economies, rely on county services for governance. Sussex County includes 22 Census-Designated Places (CDPs), such as Lewes, which are unincorporated areas identified for statistical purposes. Residents in both CDPs and other unincorporated areas depend on the county for services like road maintenance and emergency management but lack the legislative authority of incorporated municipalities.