Lebanon is a borough in Hunterdon County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 1,358, reflecting an increase of 293 from the 1,065 counted in the 2000 Census, which had in turn increased by 29 from the 1,036 counted in the 1990 Census.Lebanon was incorporated as a borough by an act of the New Jersey Legislature on March 26, 1926, from portions of Clinton Township, based on the results of a referendum held on April 20, 1926. Additional portions of Clinton Township were annexed in 1962.The borough is located north of the Round Valley Reservoir. The Borough was known in the early part of the 19th century as Jacksonville and later as Lebanonville, Lebanonville Depot and finally Lebanon, a station on the Central Railroad of New Jersey. The center of Lebanon has changed little in the past century. The Dutch Reformed Church is one of the oldest churches in the County.