Kelseyville (formerly, Kelsey, Kelsey Creek, Kelsey Town, Peartown, and Uncle Sam) is a census-designated place (CDP) in Lake County, California, United States. Kelseyville is located 6 miles (9.7 km) southeast of Lakeport, at an elevation of 1384 feet (422 m). The population was 2,928 at the 2000 census.
According to the United States Census Bureau, the CDP has a total area of 3.2 square miles (8.4 km²), all of it land.
The place was originally called Kelsey Town in honor of Andrew Kelsey, the first American settler in Lake County. The first blacksmith's opened in 1857. The place was called Uncle Sam after Mount Uncle Sam (now Mount Konocti). The Uncle Sam post office opened in 1858 and changed its name to Kelseyville in 1882.
As of the census of 2000, there were 2,928 people, 1,095 households, and 724 families residing in the CDP. The population density was 905.5 people per square mile (350.0/km²). There were 1,175 housing units at an average density of 363.4/sq mi (140.5/km²). The racial makeup of the CDP was 76.98% White, 0.14% Black or African American, 2.66% Native American, 0.89% Asian, 14.58% from other races, and 4.75% from two or more races. 28.76% of the population were Hispanic or Latino of any race.
There were 1,095 households out of which 33.7% had children under the age of 18 living with them, 46.9% were married couples living together, 14.8% had a female householder with no husband present, and 33.8% were non-families. 27.6% of all households were made up of individuals and 15.8% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.24.
In the CDP the population was spread out with 28.4% under the age of 18, 7.5% from 18 to 24, 26.7% from 25 to 44, 20.6% from 45 to 64, and 16.8% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 98.0 males. For every 100 females age 18 and over, there were 93.8 males.
The median income for a household in the CDP was $24,363, and the median income for a family was $28,958. Males had a median income of $26,758 versus $20,036 for females. The per capita income for the CDP was $15,651. About 12.8% of families and 15.3% of the population were below the poverty line, including 17.7% of those under age 18 and 11.1% of those age 65 or over.
In the state legislature Kelseyville is located in the 2nd Senate District, represented by Democrat Pat Wiggins, and in the 1st Assembly District, represented by Democrat Patty Berg. Federally, Kelseyville is located in California's 1st congressional district, which has a Cook PVI of D +10 and is represented by Democrat Mike Thompson.