Wilmon Whilldin Blackmar (July 25, 1841 – July 16, 1905) was a United States military officer who fought with the Union Army as a member of the 15th Pennsylvania Cavalry and the 1st West Virginia Cavalry during the American Civil War. He received his country's highest award for bravery during combat, the U.S. Medal of Honor, for his "extraordinary heroism" for taking the initiative, during a critical stage of the Battle of Five Forks on April 1, 1865, to lead a successful advance upon the enemy while fighting with the 1st West Virginia Cavalry. His award was conferred on October 23, 1897.