Oradell is a borough in Bergen County, New Jersey, United States. At the 2010 United States Census, the borough's population was 7,978, reflecting a decline of 69 (-0.9%) from the 8,047 counted in the 2000 Census, which had in turn increased by 23 (+0.3%) from the 8,024 counted in the 1990 Census. The borough includes a dam on the Hackensack River that forms the Oradell Reservoir.