Hackensack is a city in Bergen County, New Jersey, United States and the county seat of Bergen County. Although informally called Hackensack, it was officially named New Barbadoes Township until 1921. As of the United States 2000 Census, the city population was 42,677. The Census Bureau's 2005 population estimate indicates a total population of 43,735. It is located approximately 7 miles west of Manhattan and 12 miles south of Rockland County, New York. From a number of locations one can see the New York City skyline. Hackensack apartments for rent comparison page shows most up to date rent information on Hackensack apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.