Frederick Clarence Buck (1843 – July 15, 1905) was a United States soldier who fought with the Union Army as a member of the 21st Connecticut Infantry Regiment during the American Civil War. He received his nation's highest award for bravery during combat, the U.S. Medal of Honor, for his actions during the Battle of Chaffin's Farm in Virginia on September 29, 1864. That award was conferred on April 6, 1865.