John Elisha Phelps (April 6, 1839 - September 17, 1921) was a Union officer during the American Civil War who was promoted to brevet brigadier general of volunteers on March 13, 1865. The former Springfield, Missouri-born grocer and cattle trader started his military career as a secret agent for Nathaniel Lyon in 1861. He was wounded in the leg at the Battle of Pea Ridge. In 1862, he became an aide-de-camp on the staff of Brigadier General Eugene Asa Carr. While recovering from malaria, he organized the 2nd Arkansas Cavalry and was made its colonel on March 18, 1864. After the war he became a farmer and a miner and later moved to Tacoma, Washington and eventually died in Pasadena, California.