Tenafly is a borough in Bergen County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 15,409, an increase of 921 from the 2010 census count of 14,488, which in turn reflected an increase of 682 from the 13,806 counted in the 2000 census. Tenafly is a suburb of New York City. The borough has been one of the state's highest-income communities.