Cresskill is a borough located in Bergen County, New Jersey. The administrative structure of New Jersey consists of three levels: State → County → Municipality, with Cresskill being the lowest unit, the municipality. New Jersey has various types of local government entities, including boroughs, townships, cities, towns, and villages, and Cresskill is classified as a borough.

Bergen County is located at the northeastern tip of New Jersey and borders New York State and the Hudson River. The county has over 70 municipalities, making it one of the counties with the highest number of municipalities in the United States. Cresskill is situated in the northeastern part of the county, bordered by the municipalities of Alpine to the north, Demarest to the south, Englewood Cliffs to the east, and towns in the Northern Valley region to the west. The administrative center of Bergen County is Hackensack, where the Bergen County Courthouse is also located.

The official ZIP code for Cresskill borough is 07626. In the U.S. postal system, ZIP codes are a key unit of the address system, widely used for mail delivery, school district boundaries, insurance rates, and real estate assessments. The 07626 ZIP code applies to the entire borough of Cresskill, and to avoid confusion with adjacent towns, it should be accurately noted with the city name (Cresskill) when providing an address. Major ZIP codes surrounding Cresskill include Demarest 07627, Alpine 07620, and Englewood Cliffs 07632.

In addition to the official administrative divisions, there are also unofficial area names commonly used by residents in Cresskill. Broadly, the areas can be divided into a downtown commercial district, northern residential areas, and southern residential areas, although there are no distinct boundaries. The intersection near Union Avenue and Bank Street serves as the administrative and commercial center, while moving north towards Alpine, there tends to be an increase in large-lot upscale single-family homes. The residential area to the south towards Demarest generally has smaller lot homes.

The Cresskill Borough Council is composed based on election wards. Typically, it is divided into three election wards, with two council members elected from each ward. The ward boundaries may be adjusted based on population distribution, and the latest ward information can be checked through the borough hall or the Bergen County Board of Elections. Voter registration is conducted through the county election office, and citizens residing in Cresskill can participate in elections at the state, county, and borough levels.

School district boundaries often align with borough boundaries, but at the high school level, there may be joint regional high school districts with nearby towns. Cresskill public schools are overseen by the Cresskill School District, with students attending schools within Cresskill from elementary through 8th grade, and Cresskill High School operating independently for grades 9-12. School district boundaries and assignment information can be verified through the town's school district website or borough hall.

Fire services are provided by the Cresskill Volunteer Fire Department, and emergency medical services (EMS) are also operated on a volunteer basis. Public utilities (water, sewage, etc.) are managed partly by the town and partly contracted with Bergen County or private companies. Electricity is supplied by PSE&G (Public Service Electric and Gas), and gas is provided by PSE&G or other suppliers. When moving to Cresskill, utility account transfers or new setups must be applied for directly with each supplier.