The 1940 Democratic National Convention was held at the Chicago Stadium in Chicago, Illinois from July 15 to July 18, 1940. The convention resulted in the nomination of President Franklin D. Roosevelt for an unprecedented third term. Secretary of Agriculture Henry A. Wallace from Iowa was nominated for vice president.

Henry Agard Wallace was an American politician, journalist, farmer, and businessman who served as the 33rd vice president of the United States, from 1941 to 1945, under President Franklin D. Roosevelt. He served as the 11th U.S. secretary of agriculture and the 10th U.S. secretary of commerce. He was the nominee of the new Progressive Party in the 1948 presidential election.