Matej Kocak (December 3, 1882 – October 4, 1918), a United States Marine Corps sergeant, was posthumously awarded both the Army and Navy Medals of Honor, for "heroism above and beyond the call of duty" in action against the enemy on July 18, 1918. Less than three months after his act of heroism he was killed in action by enemy gunfire in the Battle of Blanc Mont Ridge in France while serving as a member of the 66th Company, 5th Regiment.