M. Waldo Hatler (January 6, 1894 - August 31, 1967) was a Sergeant in the United States Army during World War I who received the Medal of Honor for heroism near Pouilly, France, November 8, 1918.

Assigned to Company B, 356th Infantry, he had risen to the rank of sergeant when, just days before the armistice, his regiment was halted by the enemy in its advance toward Germany at the Meuse River near the French village of Pouilly.

Information relative to enemy strength and disposition on the opposite bank was vitally needed and Hatler was one of several men to volunteer.

Swimming across the river, he succeeded in reaching the German lines, after another soldier, who had started with him, had been seized with cramps and drowned in midstream.

Alone he carefully and courageously reconnoitered the enemy's positions, which were held in force, and again successfully swam the river, bringing back information of great value.