As of the United States 2000 Census, the population was 608,975. It is part of the New York Metropolitan Area. There were 230,546 households and 143,630 families residing in the county. The population density was 13,044 people per square mile (5,036/km²). It is the sixth-most densely populated county in the United States, trailing only four of New York City's boroughs (all except Staten Island) and San Francisco County, California. There were 240,618 housing units at an average density of 5,154 per square mile (1,990/km²). The racial makeup of the county was 55.58% White, 13.48% Black or African American, 0.42% Native American, 9.35% Asian, 0.06% Pacific Islander, 15.48% from other races, and 5.63% from two or more races. 39.76% of the population were Hispanic or Latino of any race. According to Census 2000 9.9% were of Italian and 6.7% Irish ancestry.
By 2005, 34.6% of the population was non-Hispanic whites. 15.1% of the population was African-American. 11.0% of the population was Asian. 2.1% of the population reported two or more races. 41.0% of the population was Latino.
There were 230,546 households out of which 29.60% had children under the age of 18 living with them, 39.80% were married couples living together, 16.60% had a female householder with no husband present, and 37.70% were non-families. 29.50% of all households were made up of individuals and 9.60% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 3.27.
In the county the population was spread out with 22.60% under the age of 18, 10.40% from 18 to 24, 35.60% from 25 to 44, 20.00% from 45 to 64, and 11.40% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 96.50 males. For every 100 females age 18 and over, there were 94.20 males.
The median income for a household in the county was $40,293, and the median income for a family was $44,053. Males had a median income of $36,174 versus $31,037 for females. The per capita income for the county was $21,154. About 13.30% of families and 15.50% of the population were below the poverty line, including 22.00% of those under age 18 and 15.70% of those age 65 or over.
Hudson County is the most densely populated county in the state.
The confluence of roads and railways of the BosWash megalopolis and Northeast Corridor passing through Hudson County make it one of the Northeast's major transportation crossroads and provide access to an extensive network of interstate highways, state freeways and toll roads, and vehicular water crossings. Many long distance trains and buses pass through the county, though Amtrak and the major national bus companies – Greyhound Lines and Trailways – do not provide service within it. There many local, intrastate, and Manhattan-bound bus routes, an expanding light rail system, ferries traversing the Hudson, and commuter trains to North Jersey, the Jersey Shore, and Trenton. Much of the rail, surface transit, and ferry system is oriented to commuters traveling to Newark, lower and midtown Manhattan, and the Hudson Waterfront. Public transportation is operated by a variety of public and private corporations, notably New Jersey Transit, The Port Authority of New York and New Jersey, and NY Waterway, each of which charge customers separately for their service.
Hoboken Terminal, Bergenline Avenue at 32nd, 48th, and 91st Streets in North Hudson, Journal Square Transportation Center and Exchange Place in Jersey City are major public transportation hubs. The Port Authority Bus Terminal and Penn Station in midtown Manhattan, the World Trade Center in lower Manhattan, and Newark Penn Station also play important roles within the county's transportation network. Secaucus Junction provides access to eight commuter rail lines.
Major highways include New Jersey Routes 3, 7, 139, 185, 440, 495, Interstates 78, 95, and 280, and U.S. Routes 1 and 9, as well as the New Jersey Turnpike and The Pulaski Skyway. Automobile access to New York City is available through the Lincoln Tunnel (via Weehawken to midtown Manhattan) and the Holland Tunnel (via Jersey City to lower Manhattan), and over the Bayonne Bridge to Staten Island. County Route 501 runs the length of Hudson as Kennedy Boulevard.
New Jersey Transit bus routes 120 -129 provide service to Manhattan.
Most airports which serve Hudson County are operated by the Port Authority of New York and New Jersey