Otterville is an incorporated town in Jersey County, Illinois, United States. As of the 2010 U.S. census, the town had a total population of 126.
Otterville is located at 39°3′4″N 90°23′51″W / 39.05111°N 90.39750°W / 39.05111; -90.39750 (39.051073, -90.397601).
According to the 2010 census, Otterville has a total area of 1.01 square miles (2.62 km), all land.
As of the census of 2000, there were 120 people, 41 households, and 33 families residing in the town. The population density was 119.8 people per square mile (46.3/km²). There were 43 housing units at an average density of 42.9/sq mi (16.6/km²). The racial makeup of the town was 96.67% White, 1.67% Native American, and 1.67% from two or more races. Hispanic or Latino of any race were 2.50% of the population.
There were 41 households, out of which 41.5% had children under the age of 18 living with them, 65.9% were married couples living together, 9.8% had a female householder with no husband present, and 19.5% were non-families. 17.1% of all households were made up of individuals and 4.9% had someone living alone who was 65 years of age or older. The average household size was 2.93 and the average family size was 3.36.
In the town, the population was spread out with 34.2% under the age of 18, 5.8% from 18 to 24, 26.7% from 25 to 44, 25.0% from 45 to 64, and 8.3% who were 65 years of age or older. The median age was 34 years. For every 100 females, there were 84.6 males. For every 100 females age 18 and over, there were 92.7 males.
The median income for a household in the town was $34,063, and the median income for a family was $34,375. Males had a median income of $33,000 versus $16,000 for females. The per capita income for the town was $10,588. There were 14.7% of families and 14.6% of the population living below the poverty line, including 19.4% of under eighteens and none of those over 64.