Alexandria is a town in DeKalb County, Tennessee, United States. The population was 814 at the 2000 census.
According to the United States Census Bureau, the town has a total area of 0.9 square miles (2.3 km²), all of it land.
As of the census of 2000, there were 814 people, 349 households, and 226 families residing in the town. The population density was 901.3 people per square mile (349.2/km²). There were 383 housing units at an average density of 424.1 per square mile (164.3/km²). The racial makeup of the town was 90.17% White, 7.74% African American, 0.25% Native American, 0.12% Asian, 0.49% from other races, and 1.23% from two or more races. Hispanic or Latino of any race were 0.25% of the population.