Rockleigh (pronounced ROCK-lee) is an affluent upper middle and upper class borough in Bergen County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 531, reflecting an increase of 140 (+35.8%) from the 391 counted in the 2000 Census, which had in turn increased by 121 (+44.8%) from the 270 counted in the 1990 Census. Bordering Alpine, New Jersey, a town ranked America's most expensive zip code by Forbes, Rockleigh exudes a similar feeling with large single family homes on large plots of land. Although a more low-profile town with established families than more high profile nouveau riche neighboring towns, Rockleigh is known for preserving Old World charm and its historic roots as a Dutch colonial settlement.