Lebanon locally is the only city in Grafton County, New Hampshire, United States. The population was 13,151 at the 2010 census and an estimated 13,651 as of 2019. Lebanon is in western New Hampshire, south of Hanover, near the Connecticut River. It is the home to Dartmouth–Hitchcock Medical Center and Dartmouth College's Geisel School of Medicine, together comprising the largest medical facility between Boston, Massachusetts, and Burlington, Vermont.
Together with Hanover, New Hampshire, and White River Junction, Vermont, Lebanon is at the center of a Micropolitan Statistical Area, encompassing nearly 30 towns along the upper Connecticut River valley.
Lebanon was chartered as a town by colonial governor Benning Wentworth on July 4, 1761, one of 16 along the Connecticut River. It was named for Lebanon, Connecticut, from where many early settlers had come or would come, including the Rev. Eleazar Wheelock, who arrived in 1770 and founded Dartmouth College. Lebanon, Connecticut, was the original home of Moor's Charity School, the antecedent of Dartmouth College.
Early settlement concentrated along the Connecticut River in what is now West Lebanon, and along the Mascoma Lake region near Enfield.