Eagle Butte is a city in Dewey and Ziebach counties in South Dakota, United States. The population was 1,258 at the 2020 census. It is adjacent to the North Eagle Butte CDP.

Dewey County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 5,239. Its county seat is Timber Lake. The county was created in 1883 and organized in 1910. It was named for William P. Dewey, Territorial surveyor-general from 1873 to 1877.