Sereno Elmer Brett (October 31, 1891 – September 9, 1952) was a highly decorated brigadier general in the United States Army who fought in both World War I and World War II and played a key, if little recognized today, role in the development of armored warfare along with the creation of the U.S. Interstate Highway.

He first saw active service with the 3rd Infantry Regiment, Oregon National Guard during the Pancho Villa Expedition where they stood watch at Calexico During World War I, Brett was ordered to join the American Expeditionary Force (AEF), under the command of Major General John J. Pershing, on the Western Front in Belgium and France, to serve with the Tank Corps.

In 1919, Brett and future U.S. President Dwight D. Eisenhower toured the country's emerging paved highways with an Army caravan of 80-or-so military vehicles, Army's 1919 transcontinental motor convoy, to determine if the country could manage to move large amounts of troops and equipment quickly over long distances.

[4] During World War II he served on the staff of the 5th Armored Division in 1942–1943 as it prepared for service in the European theatre, and was promoted to brigadier general in 1942, but retired from the army in October 1943 for medical reasons.

[7] Among the important papers are personal diaries of Patton and Brett written during their deployment in France 1918, and reports of their tank operations at St. Mihiel and in the Meuse-Argonne.