De Kalb is a city in southwest Buchanan County, Missouri, United States.

[4] It was renamed in 1851 for Johann von Robais, Baron de Kalb, a major general in the American Revolutionary War.

[6] According to the United States Census Bureau, the city has a total area of 0.25 square miles (0.65 km2), all land.

The racial makeup of the city was 99.1% White, 0.5% African American, and 0.5% from two or more races.

The racial makeup of the town was 97.28% White, 0.78% Native American, and 1.95% from two or more races.

About 3.2% of families and 3.0% of the population were below the poverty line, including none of those under the age of eighteen and 2.6% of those 65 or over.