Fern Forest is a census-designated place (CDP) in Hawaiʻi County, Hawaiʻi, United States, located in the District of Puna. The population was 480 at the 2000 census. The population increased by 94.0% to 931 at the 2010 census.
Fern Forest is located at 19°28′20″N 155°7′48″W (19.472132, -155.130135).
According to the United States Census Bureau, the CDP has a total area of 12.5 square miles (32 km2), all of it land.
As of the census of 2010, there were 931 people and 399 households residing in the CDP. The population density was 74.5 people per square mile (28.6/km²). There were 460 housing units at an average density of 23.1/sq mi (8.9/km²). The racial makeup of the CDP was 49.30% White, 0.75% African American, 0.86% American Indian & Alaska Native, 7.84% Asian, 10.63% Native Hawaiian & Pacific Islander, 0.64% from other races, and 29.97% from two or more races. Hispanic or Latino of any race were 13.53% of the population.
There were 399 households out of which 20.1% had children under the age of 18 living with them. The average household size was 2.33.
In the CDP the population was spread out with 21.4% under the age of 18, 7.5% from 18 to 24, 11.6% from 25 to 34, 19.4% from 35 to 49, 31.5% from 50-64, and 8.6% who were 65 years of age or older. For every 100 females there were 117.5 males. For every 100 males there were 85.1 females.
The median income for a household in the CDP at the 2000 census was $24,519, and the median income for a family in 2000 was $33,125. Males had a median income of $40,125 versus $28,333 for females in 2000. The per capita income for the CDP was $14,958 in 2000. About 18.3% of families and 25.5% of the population were below the poverty line in 2000, including 10.3% of those under age 18 and 36.8% of those age 65 or over.