Buchanan Dam is a census-designated place in Llano County, Texas, United States. Buchanan Dam is located on the south shore of Lake Buchanan.
As of the census of 2000, there were 1,688 people, 848 households, and 545 families residing in the CDP. Of the 848 households, 11.0% had children under the age of 18 living with them, 57.1% were married couples living together, 4.5% had a female householder with no husband present, and 35.7% were not families. About 31.4% of all households were made up of individuals, and 13.8% had someone living alone who was 65 years of age or older. The median income for a household in the CDP was $32,586, and for a family was $41,216. Males had a median income of $39,286 versus $23,580 for females. The per capita income for the CDP was $25,812.
Buchanan Dam is served by the Burnet Consolidated Independent School District.