Washington is a borough in Warren County, New Jersey, United States. The borough is located in the easternmost region of the Lehigh Valley. Washington was incorporated as a borough by an act of the New Jersey Legislature on February 20, 1868, from portions of Washington Township. The borough was named for George Washington, one of more than ten communities statewide named for the first president. The Borough of Washington is surrounded by Washington Township, which is one of five municipalities in the state of New Jersey with the name "Washington Township".
Washington has a population of over 6,452 people. Washington also forms part of the wider Allentown-Bethlehem-Easton metropolitan area which has a population of over 844,052 people.