William Franklin Raynolds (March 17, 1820 – October 18, 1894) was a U.S. Army officer, explorer, engineer, Mexican War and Civil War veteran who is best known for leading the 1859-1860 Raynolds Expedition while serving as a member of the U.S. Army Corps of Topographical Engineers. Raynolds was also promoted to temporary Brevet Brigadier General in 1865 for meritorious services during the Civil War and retired from the Corps of Engineers a full Colonel on March 17, 1884, after a 40-year military career.