Lyme is a town in Jefferson County, New York, United States. The population was 2,185 at the 2010 census.
According to the United States Census Bureau, the town of Lyme has a total area of 107.0 square miles (277.1 km), of which 55.8 square miles (144.6 km) are land and 51.2 square miles (132.6 km), or 47.83%, are water. The western boundary of Lyme is Lake Ontario, but most of the coastline comprises the shoreline of Chaumont Bay, which is entirely within Lyme.
New York State Route 12E is an east-west highway through Lyme.
As of the census of 2000, there were 2,015 people, 813 households, and 573 families residing in the town. The population density was 35.9 people per square mile (13.9/km²). There were 2,183 housing units at an average density of 38.9 per square mile (15.0/km²). The racial makeup of the town was 97.42% White, 1.14% African American, 0.40% Native American, 0.10% Asian, 0.15% from other races, and 0.79% from two or more races. Hispanic or Latino of any race were 0.79% of the population.
There were 813 households out of which 27.4% had children under the age of 18 living with them, 60.4% were married couples living together, 7.1% had a female householder with no husband present, and 29.5% were non-families. 24.5% of all households were made up of individuals and 13.0% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 2.94.
In the town, the population was spread out with 22.7% under the age of 18, 6.7% from 18 to 24, 25.8% from 25 to 44, 27.2% from 45 to 64, and 17.6% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 99.5 males. For every 100 females age 18 and over, there were 96.7 males.
The median income for a household in the town was $37,569, and the median income for a family was $43,068. Males had a median income of $32,554 versus $23,333 for females. The per capita income for the town was $19,522. About 6.2% of families and 10.2% of the population were below the poverty line, including 13.2% of those under age 18 and 7.1% of those age 65 or over.