|Lake Nacimiento, California|
|— CDP —|
Location in San Luis Obispo County and the state of California
|County||San Luis Obispo|
|- Total||7.4 sq mi (19.2 km2)|
|- Land||7.4 sq mi (19.2 km2)|
|- Water||0 sq mi (0 km2)|
|Elevation||984 ft (300 m)|
|- Density||294.1/sq mi (113.3/km2)|
|Time zone||Pacific (PST) (UTC-8)|
|- Summer (DST)||PDT (UTC-7)|
|GNIS feature ID||1867034|
Lake Nacimiento is located at .(35.737585, -120.881328)
According to the United States Census Bureau, the CDP has a total area of 7.4 square miles (19.2 km²), all of it land.
As of the census of 2000, there were 2,176 people, 904 households, and 676 families residing in the CDP. The population density was 293.1 people per square mile (113.2/km²). There were 1,283 housing units at an average density of 172.8/sq mi (66.8/km²). The racial makeup of the CDP was 93.52% White, 0.32% African American, 1.33% Native American, 0.37% Asian, 1.06% from other races, and 3.40% from two or more races. Hispanic or Latino of any race were 7.31% of the population.
There were 904 households out of which 26.9% had children under the age of 18 living with them, 64.6% were married couples living together, 6.2% 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 6.1% had someone living alone who was 65 years of age or older. The average household size was 2.41 and the average family size was 2.74.
In the CDP the population was spread out with 21.6% under the age of 18, 4.9% from 18 to 24, 26.3% from 25 to 44, 29.8% from 45 to 64, and 17.4% who were 65 years of age or older. The median age was 43 years. For every 100 females there were 102.6 males. For every 100 females age 18 and over, there were 103.1 males.
The median income for a household in the CDP was $54,958, and the median income for a family was $57,206. Males had a median income of $41,447 versus $34,219 for females. The per capita income for the CDP was $22,798. About 2.6% of families and 4.7% of the population were below the poverty line, including 3.9% of those under age 18 and 13.0% of those age 65 or over.
In the state legislature Lake Nacimiento is located in the 15th Senate District, represented by Republican Abel Maldonado, and in the 33rd Assembly District, represented by Republican Sam Blakeslee. Federally, Lake Nacimiento is located in California's 22nd congressional district, which has a Cook PVI of R +16 and is represented by Republican Kevin McCarthy.