Elfin Cove is located off Cross Sound on Chichagof Island at coordinates 58°11′56″N 136°21′19″W / 58.19889°N 136.35528°W / 58.19889; -136.35528 (58.198786, -136.355358). The CDP occupies the northern end of the Inian Peninsula; the actual settlement of Elfin Cove within the CDP, and its namesake harbor, are on the western side of the peninsula.
According to the United States Census Bureau, the CDP has a total area of 10.4 square miles (26.9 km2), of which 10.2 square miles (26.4 km2) are land and 0.2 square miles (0.5 km2), or 1.73%, are water.
According to the Köppen climate classification system, Elfin Cove has an oceanic climate (Cfb).
Elfin Cove first appeared on the 1940 U.S. Census as an unincorporated village. It appeared again on the 1950 census, but did not appear in 1960. It was returned again in 1970 and made a census-designated place (CDP) in 1980.
As of the census of 2000, there were 32 people, 15 households, and 9 families residing full-time in the CDP.
Among full-time residents, the population density was 3.0 people per square mile (1.2/km²). There were 35 housing units at an average density of 3.3/sq mi (1.3/km²). The racial makeup of the CDP was 93.75% White, 3.12% Pacific Islander, and 3.12% from two or more races.
There were 15 households out of which 20.0% had children under the age of 18 living with them, 53.3% were married couples living together, and 40.0% were non-families. 26.7% of all households were made up of individuals and 6.7% had someone living alone who was 65 years of age or older. The average household size was 2.13 and the average family size was 2.67.
In the CDP, the population was spread out with 15.6% under the age of 18, 3.1% from 18 to 24, 28.1% from 25 to 44, 37.5% from 45 to 64, and 15.6% who were 65 years of age or older. The median age was 48 years. For every 100 females there were 146.2 males. For every 100 females age 18 and over, there were 170.0 males.
The median income for a household in the CDP was $33,750, and the median income for a family was $33,750. Males had a median income of $48,750 versus $0 for females. The per capita income for the CDP was $15,089. There were no families and 5.6% of the population living below the poverty line, including no under eighteens and none of those over 64.