New Haven County is located in the south central part of the U.S. state of Connecticut. As of 2000 the population was 824,008. Two of the state's largest cities, New Haven and Waterbury are part of New Haven County.

County governments were abolished in Connecticut in 1960. Thus, as is the case with all eight of Connecticut's counties, there is no county government, and no county seat. Until 1960, the city of New Haven was the county seat. In Connecticut, towns are responsible for all local government activities, including fire and rescue, snow removal and schools. In some cases, neighboring towns will share certain activities, e.g. schools, health, etc. However, New Haven County is merely a group of towns on a map, and has no particular authority. The state judicial system, however, remains divided by county, and drivers receiving speeding tickets on state or interstate highways, for example, are assigned to courts based on a county geographical system. The county Sheriff system was abolished by voters and replaced by State Judicial Marshals.