Irvington is a township in Essex County, New Jersey, United States. As of the 2010 United States Census, the township had a total population of 53,926, having declined by 6,769 (-11.2%) from the 60,695 counted in the 2000 Census, which had in turn declined by 323 (-0.5%) from the 61,018 counted in the 1990 Census.