According to the 2010 Census, the county had a total area of 62.31 square miles (161.4 km²), including 46.19 square miles (119.6 km²) of land (74.1%) and 16.12 square miles (41.8 km²) of water (25.9%).
Based on land area, it is the smallest of New Jersey's 21 counties, less than half the size of the next smallest (Union County) and the eighth-smallest of all counties in the United States.

Hudson is located in the heart of New York metropolitan area in northeastern New Jersey.

It is bordered by the Hudson River and Upper New York Bay to the east; Kill Van Kull to the south; Newark Bay and the Hackensack River or the Passaic River to the west; its only land border is shared with Bergen County to the north and west.

The topography is marked by the New Jersey Palisades in the north with cliffs overlooking the Hudson to the east and less severe cuesta, or slope, to the west.
They gradually level off to the southern peninsula, which is coastal and flat.
The western region, around the Hackensack and Passaic is part of the New Jersey Meadowlands.
Much of the land along the county's extensive shoreline and littoral zone was created by land reclamation.

The highest point, at 260 feet (79 m) above sea level, is in West New York; the lowest point is at sea level.
North Bergen is the city with the second most hills per square mile in the United States behind San Francisco.

Ellis Island and Liberty Island, opposite Liberty State Park, lie entirely within Hudson County's waters, which extend to the New York state line.
Liberty Island is part of New York.
Largely created through land reclamation, Ellis Island covers a land area of 27.5 acres (11.1 ha), with the 2.74-acre (1.11 ha) natural island and contiguous areas comprising a 3.3 acres (1.3 ha) exclave of New York.
Shooters Island, in the Kill van Kull, is also shared with New York.
Robbins Reef Light sits atop a reef which runs parallel the Bayonne and Jersey City waterfront.

Much of the county lies between the Hackensack and Hudson Rivers on geographically long narrow peninsula, (sometimes called Bergen Neck), that is a contiguous urban area where it's often difficult to know when one's crossed a civic boundary.
These boundaries and the topography-including many hills and inlets-create very distinct neighborhoods.
Kennedy Boulevard runs the entire length of the peninsula.
Numerous cuts for rail and vehicular traffic cross Bergen Hill.

Counties adjacent to Hudson are New York County, New York and Kings County, New York to the east; Essex County and Union County to west; Richmond County, New York to the south; and Bergen County, the only one with which it shares a land border, to the north and west.
Given its proximity to Manhattan, it is sometimes referred to as New York City's sixth borough.
According to the 2010 Census, the county had a total area of 62.31 square miles (161.4 km²), including 46.19 square miles (119.6 km²) of land (74.1%) and 16.12 square miles (41.8 km²) of water (25.9%). Based on land area, it is the smallest of New Jersey's 21 counties, less than half the size of the next smallest (Union County) and the eighth-smallest of all counties in the United States.
Hudson is located in the heart of New York metropolitan area in northeastern New Jersey.
It is bordered by the Hudson River and Upper New York Bay to the east; Kill Van Kull to the south; Newark Bay and the Hackensack River or the Passaic River to the west; its only land border is shared with Bergen County to the north and west.
The topography is marked by the New Jersey Palisades in the north with cliffs overlooking the Hudson to the east and less severe cuesta, or slope, to the west. They gradually level off to the southern peninsula, which is coastal and flat. The western region, around the Hackensack and Passaic is part of the New Jersey Meadowlands. Much of the land along the county's extensive shoreline and littoral zone was created by land reclamation.
The highest point, at 260 feet (79 m) above sea level, is in West New York; the lowest point is at sea level. North Bergen is the city with the second most hills per square mile in the United States behind San Francisco.
Ellis Island and Liberty Island, opposite Liberty State Park, lie entirely within Hudson County's waters, which extend to the New York state line. Liberty Island is part of New York. Largely created through land reclamation, Ellis Island covers a land area of 27.5 acres (11.1 ha), with the 2.74-acre (1.11 ha) natural island and contiguous areas comprising a 3.3 acres (1.3 ha) exclave of New York. Shooters Island, in the Kill van Kull, is also shared with New York. Robbins Reef Light sits atop a reef which runs parallel the Bayonne and Jersey City waterfront.
Much of the county lies between the Hackensack and Hudson Rivers on geographically long narrow peninsula, (sometimes called Bergen Neck), that is a contiguous urban area where it's often difficult to know when one's crossed a civic boundary. These boundaries and the topography-including many hills and inlets-create very distinct neighborhoods. Kennedy Boulevard runs the entire length of the peninsula. Numerous cuts for rail and vehicular traffic cross Bergen Hill.
Counties adjacent to Hudson are New York County, New York and Kings County, New York to the east; Essex County and Union County to west; Richmond County, New York to the south; and Bergen County, the only one with which it shares a land border, to the north and west. Given its proximity to Manhattan, it is sometimes referred to as New York City's sixth borough.
Hudson County, New Jersey