Frenchtown is a borough in Hunterdon County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 1,373, reflecting a decline of 115 (-7.7%) from the 1,488 counted in the 2000 Census, which had in turn declined by 40 (-2.6%) from the 1,528 counted in the 1990 Census.