Jersey City is the second-most populous city in the U.S. state of New Jersey, after Newark. It is the seat of Hudson County as well as the county's largest city. The 2020 U.S. census showed that the city's population was 292,449 in 2020, ranking as the 71st-most-populous incorporated place in the nation. The 2020 census represents an increase of 18.1% from the 2010 United States census, when the city's population was at 247,597. Jersey City, with a population density of 17,396 inhabitants per square mile as of 2013, had the third-highest density of any U.S. city with over 100,000 people, behind only New York City and San Francisco.
After a peak population of 316,715 measured in the 1930 census, the city's population saw a half-century-long decline to 223,532 in the 1980 census. Since then, the city's population has rebounded, with the 2020 population reflecting an increase of 44,852 from the 247,597 counted in the 2010 Census, which had an increase of 7,542 from the 240,055 counted in the 2000 census, which had in turn increased by 11,518 from the 228,537 counted in the 1990 census.