Lagunitas-Forest Knolls is a census-designated place, composed of two unincorporated areas in the western half of the San Geronimo Valley in Marin County, California, United States. The population was 1,835 at the 2000 census.
The two towns are locally seen as separate, geographically divided by narrow points in the San Geronimo Valley, and each with its own small commercial center. Both are primarily residential. Lagunitas' Zip Code is 94938 while that of Forest Knolls is 94933.
According to the United States Census Bureau, the CDP has a total area of 11.0 square kilometers (4.2 sq mi), all land.
The towns line the western end of the San Geronimo Valley, extending into the forested south ridges and slightly into the grassier northern ones.
Lagunitas is on the eastern border of Samuel P. Taylor State Park. Like the park, Lagunitas-Forest Knolls and the surrounding environs are lushly vegetated with large areas of coniferous forests.
Hiking and horseback riding are popular in the hills above the towns.
As of the census of 2000, there were 1,835 people, 745 households, and 475 families residing in the CDP. The population density was 430.5 people per square mile (166.3/km²). There were 776 housing units at an average density of 182.1/sq mi (70.3/km²). The racial makeup of the CDP was 88.61% White, 1.42% African American, 0.93% Native American, 1.36% Asian, 0.11% Pacific Islander, 3.38% from other races, and 4.20% from two or more races. Hispanic or Latino of any race were 5.56% of the population.
There were 745 households out of which 35.2% had children under the age of 18 living with them, 45.1% were married couples living together, 12.6% had a female householder with no husband present, and 36.2% were non-families. 26.3% of all households were made up of individuals and 3.0% had someone living alone who was 65 years of age or older. The average household size was 2.43 and the average family size was 2.87.
In the CDP the population was spread out with 24.2% under the age of 18, 5.2% from 18 to 24, 29.6% from 25 to 44, 35.4% from 45 to 64, and 5.6% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 97.7 males. For every 100 females age 18 and over, there were 96.5 males.
The median income for a household in the CDP was $55,917, and the median income for a family was $72,411. Males had a median income of $60,035 versus $40,625 for females. The per capita income for the CDP was $31,504. About 4.1% of families and 6.0% of the population were below the poverty line, including 3.4% of those under age 18 and 2.0% of those age 65 or over.