Coordinates: 44°51′29″N 73°27′46″W / 44.8580956°N 73.4629136°W / 44.8580956; -73.4629136
According to the United States Census Bureau, the town of Chazy has a total area of 61.3 square miles (158.8 km), of which 54.2 square miles (140.3 km) is land and 7.2 square miles (18.6 km), or 11.68%, is water.
The eastern boundary of the town, in the center of the western channel of Lake Champlain, is the state border with Vermont. The Little Chazy River enters Lake Champlain north of Chazy Landing.
The Adirondack Northway (Interstate 87) and U.S. Route 9 are north-south highways through the town. New York State Route 191 is an east-west highway entirely within the town. NY 22 is a north-south highway in the western part of Chazy.
As of the census of 2000, there were 4,181 people, 1,566 households, and 1,171 families residing in the town. The population density was 77.2 people per square mile (29.8/km²). There were 1,841 housing units at an average density of 34.0 per square mile (13.1/km²). The racial makeup of the town was 97.94% White, 0.31% African American, 0.41% Native American, 0.50% Asian, 0.10% from other races, and 0.74% from two or more races. Hispanic or Latino of any race were 0.69% of the population.
There were 1,566 households out of which 36.4% had children under the age of 18 living with them, 62.1% were married couples living together, 8.0% had a female householder with no husband present, and 25.2% were non-families. 19.1% of all households were made up of individuals and 8.2% had someone living alone who was 65 years of age or older. The average household size was 2.64 and the average family size was 3.00.
In the town, the population was spread out with 26.7% under the age of 18, 7.5% from 18 to 24, 31.3% from 25 to 44, 23.1% from 45 to 64, and 11.4% who were 65 years of age or older. The median age was 37 years. For every 100 women there were 97.2 men. For every 100 women age 18 and over, there were 95.6 men.
The median income for a household in the town was $41,504, and the median income for a family was $47,589. Males had a median income of $32,825 versus $28,542 for females. The per capita income for the town was $18,125. About 8.0% of families and 10.0% of the population were below the poverty line, including 12.1% of those under age 18 and 5.4% of those age 65 or over.