Guttenberg () is a town in the northern part of Hudson County, New Jersey, United States. As of the 2010 United States Census, the town's population was 11,176. In the 2010 Census, it was the most densely populated incorporated municipality in the United States, as well as one of the most densely populated municipalities worldwide, with 57,116 people per square mile (22,052/km2) of land area. Only four blocks wide, Guttenberg has been variously ranked as the ninth-smallest municipality in the state (based on data from the U.S. Census Bureau) or as the state's seventh-smallest municipality (based on data from the New Jersey Department of Environmental Protection).
The population increased by 369 (+3.4%) from the 10,807 counted in the 2000 Census, which had in turn increased by 2,539 (+30.7%) from the 8,268 counted in the 1990 Census. As of the 2010 Census, almost one-fifth of the town's population resides in the Galaxy Towers, a trio of residential skyscrapers overlooking the Hudson River.
The current population growth and density in Guttenberg represents a significant change since 1983, when it was described by The New York Times, as "an old community of two-story row houses, small stores and light industry."
Guttenberg was formerly a farm owned by William Cooper, sold in 1853 to a group of New Yorkers, who had formed the Weehawken Land and Ferry Association. Like nearby Union Hill, it was subdivided and lots were sold mostly to Germans. The company ran two ferries, the Hultz and the Flora, which crossed the Hudson from the landings at the foot of Bulls Ferry Road, Pleasant Valley, Fort Lee, and Spring Street in Manhattan.
Guttenberg was formed as a town on March 9, 1859, from portions of North Bergen Township, but remained as a part of the township that was not fully independent. Guttenberg became part of Union Township when it was formed on February 28, 1861, and became fully independent as of April 1, 1878. The municipality takes its name from Johannes Gutenberg, the inventor of the European version of the printing press, though other sources indicate that the name derives from "good village" in German.
Galaxy Towers, developed by Prudential Insurance Company, were built in the late 1970s on Boulevard East.