Samuel Perkins Spear (1815 – May 4, 1875) was an American soldier who saw combat in the Seminole Wars, the Mexican–American War, and the American Civil War. Serving primarily in the cavalry, he received a brevet appointment as a brigadier general for his actions as a brigade commander in the Cavalry Division of the XVIII Corps, Army of the James, at the Battle of Fair Oaks & Darbytown Road during the Siege of Petersburg.