Manalapan Township (, mə-NAL-ə-PIN) is a township in Monmouth County, New Jersey, United States. It is located in the New York Metropolitan Area. As of the 2010 United States Census, the township's population was 38,872, representing an increase of 5,449 (+16.3%) from the 33,423 counted in the 2000 Census, which had in turn increased by 6,707 (+25.1%) from the 26,716 counted in the 1990 Census.
The name "Manalapan" is derived from a word in the Lenape language that would mean either "land of good bread", "good land to settle upon", "good bread" or "covered swamp with edible roots".
The Battle of Monmouth was fought in 1778 on land that is now part of Manalapan and Freehold townships. Monmouth Battlefield State Park occupies 2,928 acres (1,185 ha) in the two townships.
Manalapan Township was formed by an act of the New Jersey Legislature on March 9, 1848, from portions of Freehold Township. Englishtown was formed as a borough from portions of Manalapan on January 4, 1888, based on the results of a referendum held the previous day.
According to the United States Census Bureau, the township had a total area of 30.88 square miles (79.99 km2), including 30.65 square miles (79.39 km2) of land and 0.23 square miles (0.60 km2) of water (0.75%). The township has an elevation of 82 feet (25 m).
The township completely surrounds Englishtown, making it part of 21 pairs of "doughnut towns" in the state, where one municipality entirely surrounds another. The township borders the municipalities of Freehold Township, Marlboro Township and Millstone Township in Monmouth County; and Monroe Township and Old Bridge Township in Middlesex County.
Yorketown (with a 2010 Census population of 6,535) is an unincorporated community and census-designated place (CDP) located within Manalapan Township.
Other unincorporated communities, localities and place names located partially or completely within the township include Cahills Corners, Clarks Mills, Elton, Gordons Corner, Lafayette Mills, Millhurst, Monmouth Heights, Oakland Mills, Smithburg, Taylors Mills, Tennent, Tracey, Whittier Oaks and Woodville.
According to the A. W. Kuchler U.S. potential natural vegetation types, Manalapan Township, New Jersey would have an Appalachian Oak (104) vegetation type with an Eastern Hardwood Forest (25) vegetation form.
The 2010 United States Census counted 38,872 people, 13,263 households, and 10,663 families in the township. The population density was 1,270.0 inhabitants per square mile (490.3/km2). There were 13,735 housing units at an average density of 448.8 per square mile (173.3/km2).