Ahtanum (/əˈtɛnəm/)[3] is a census-designated place (CDP) in Yakima County, Washington.

[4] According to the United States Census Bureau, the CDP has a total area of 9.7 square miles (25.1 km2), all of it land.

As of the census[2] of 2000, there were 4,181 people, 1,467 households, and 1,150 families residing in the CDP.

The racial makeup of the CDP was 90.77% White, 0.74% African American, 1.03% Native American, 0.45% Asian, 0.02% Pacific Islander, 4.81% from other races, and 2.18% from two or more races.

16.9% of all households were made up of individuals, and 7.1% had someone living alone who was 65 years of age or older.