Lebanon Township is a township located at the northernmost point of Hunterdon County, New Jersey, United States. As of the 2010 United States Census, the township's population was 6,588, reflecting an increase of 772 (+13.3%) from the 5,816 counted in the 2000 Census, which had in turn increased by 137 (+2.4%) from the 5,679 counted in the 1990 Census.
Lebanon Township was first mentioned on October 26, 1731, as having been formed partly from the now-defunct Amwell Township, though the exact circumstances of its formation are unknown. Lebanon Township was incorporated as one of New Jersey's initial 104 townships by an Act of the New Jersey Legislature on February 21, 1798. Portions of the township have been take to form Tewksbury Township (March 11, 1755), Clinton Township (April 12, 1841), High Bridge borough (February 19, 1898), Junction borough (February 20, 1895, now known as Hampton borough), Califon borough (April 2, 1898) and Glen Gardner borough (March 26, 1919).
Lebanon Township is the extreme northern township of Hunterdon County. It borders both Warren and Morris Counties. When Lebanon Township was created in 1731, its original borders extended from the Musconetcong River to Readington Township.