Middletown Township is a township in Monmouth County, New Jersey, United States. As of the 2020 United States Census, the township had a total population of 67,106, making it the most-populous municipality in the county and the state's 16th largest municipality by population, having seen an increase of 584 residents (0.9%) from its population of 66,522 in the 2010 Census. In 2016, SafeWise named Middletown Township as the fifth-safest city in America to raise a child; the township was the highest ranked of the 12 communities in New Jersey included on the list.