According to the United States Census Bureau, the CDP has a total area of 1.9 square miles (4.9 km²), of which, 1.2 square miles (3.2 km²) of it is land and 0.6 square miles (1.7 km²) of it (34.21%) is water.
Klukwan is an enclave of Haines Borough, Alaska. Although Klukwan is located in the Hoonah-Angoon Census Area of the Unorganized Borough, it is entirely surrounded by territory of Haines Borough, and therefore cut off from the rest of the Census Area.
There were 44 households out of which 54.5% had children under the age of 18 living with them, 45.5% were married couples living together, 15.9% had a female householder with no husband present, and 27.3% were non-families. 25.0% of all households were made up of individuals and 6.8% had someone living alone who was 65 years of age or older. The average household size was 3.16 and the average family size was 3.75.
In the CDP the population was spread out with 33.1% under the age of 18, 13.7% from 18 to 24, 23.7% from 25 to 44, 23.0% from 45 to 64, and 6.5% who were 65 years of age or older. The median age was 27 years. For every 100 females there were 104.4 males. For every 100 females age 18 and over, there were 121.4 males.
The median income for a household in the CDP was $30,714, and the median income for a family was $31,563. Males had a median income of $26,250 versus $26,250 for females. The per capita income for the CDP was $11,612. There were none of the families and 1.5% of the population living below the poverty line, including no under eighteens and none of those over 64.