Waterville Valley is a town in Grafton County, New Hampshire, United States. The population was 247 at the 2010 census.
According to the United States Census Bureau, the town has a total area of 64.9 square miles (168 km), of which 0.04 sq mi (0.10 km) is water, comprising 0.05% of the town. The highest point in Waterville Valley is the North Peak of Mount Tripyramid, at 4,180 feet (1,270 m) above sea level.
As of the census of 2000, there were 257 people, 121 households, and 75 families residing in the town. The population density was 4.0 people per square mile (1.5/km²). There were 1,097 housing units at an average density of 16.9 per square mile (6.5/km²). The racial makeup of the town was 97.28% White, 1.95% Asian, 0.78% from other races. Hispanic or Latino of any race were 1.56% of the population.
There were 121 households out of which 27.3% had children under the age of 18 living with them, 45.5% were married couples living together, 9.1% had a female householder with no husband present, and 38.0% were non-families. 34.7% of all households were made up of individuals and 6.6% had someone living alone who was 65 years of age or older. The average household size was 2.12 and the average family size was 2.72.
In the town, the population was spread out with 22.2% under the age of 18, 6.6% from 18 to 24, 20.6% from 25 to 44, 37.0% from 45 to 64, and 13.6% who were 65 years of age or older. The median age was 45 years. For every 100 females, there were 104.0 males. For every 100 females age 18 and over, there were 108.3 males.
The median income for a household in the town was $40,417, and the median income for a family was $55,625. Males had a median income of $34,167 versus $34,063 for females. The per capita income for the town was $26,400. About 6.8% of families and 6.2% of the population were below the poverty line, including 6.7% of those under the age of eighteen and none of those sixty five or over.