Sumner Sewall (June 17, 1897 – January 25, 1965) was an American Republican politician and airline executive who served as the 58th Governor of Maine from 1941 to 1945.

A native of Bath, Maine, Sewall dropped out of Harvard College in 1917 to go to Europe to aid the Allies during World War I. Sewall served first in the American Ambulance Field Service from February through August 1917, then in the U.S. Army Signal Corps, then finally as a fighter pilot in the U.S. Army Air Service, becoming an ace by scoring seven victories.

He was promoted to Flight Commander, and went on to score five victories over enemy planes between 3 June and 18 September 1918, sharing a couple of them with future general James Knowles and Edward Peck Curtis.

[1] Sewall returned home with the Distinguished Service Cross with oak leaf cluster, the French Legion of Honor, the Croix de Guerre and the Order of the Crown of Belgium.

In 1948, Sewall finished a distant third in the Republican primary for Maine's open United States Senate seat, which ended his political career.