Saddle River is a borough in Bergen County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 3,152, reflecting a decline of 49 (-1.5%) from the 3,201 counted in the 2000 Census, which had in turn increased by 251 (+8.5%) from the 2,950 counted in the 1990 Census.Saddle River is one of the wealthiest small municipalities in the United States and was ranked 9th in New Jersey in per capita income as of the 2010 Census.