Harlon Henry Block (November 6, 1924 – March 1, 1945) was a United States Marine during World War II. Born in Yorktown, Texas, Block joined the Marine Corps in November 1943 and subsequently participated in combat action on Bougainville and Iwo Jima where he was killed in action. He is best known as one of the six men photographed raising the flag on Iwo Jima.