Anton Casimir Dilger (13 February 1884 – 17 October 1918) was a German-American medical doctor and a main actor in the German biological warfare sabotage program during World War I. His father, Hubert Dilger, was a United States Army captain who had received the Medal of Honor for his work as an artilleryman at the Battle of Chancellorsville (1863) during the American Civil War. Dilger eventually fled to Madrid, Spain, where he died during the 1918 flu pandemic.