Port Republic is a city on the Mullica River, located in Atlantic County, in the U.S. state of New Jersey. As of the 2020 United States census, the city's population was 1,101, a decrease of 14 from the 2010 census count of 1,115, which in turn reflected an increase of 78 from the 1,037 counted in the 2000 census. It is a dry town, where alcohol is not permitted to be sold by law.