The Battle of Dead Buffalo Lake was fought between United States forces and Sioux Indians of the Dakota Territory.

A combined force of Santee and Teton Sioux forces had been defeated at the battle of Big Mound. They fled that battlefield and were chased endlessly by U.S. cavalry. General Henry Hastings Sibley, the cavalry leader, and the cavalry traveled 14 miles before catching up to the Natives the next day, July 26.

The Sioux were ready for battle, but neither side made any initial attacks. The heaviest fighting occurred when the warriors attempted to flank the U.S. camp, but their attack was called off after encountering resistance from U.S. infantry and mounted forces. The Indians withdrew from the field and were again in retreat with Sibley's forces close behind.