Leutnant Helmut Dilthey IC (9 February 1894 - 9 July 1918) was a German pilot who became a World War I flying ace credited with seven aerial victories.
Dilthey was one of the first German military aviators, joining its military aviation in November 1914.
From 18 May 1915 through March 1917, he would serve in Flieger-Abteilung 50, flying reconnaissance and bombing missions in Russia while winning both classes of the Iron Cross and being promoted to leutnant.
He also gained some experience on fighters with an assigned Fokker Eindekker.
When the Luftstreitkräfte founded dedicated fighter units, Dilthey volunteered for fighter duty.
After training, he served under Hermann Göring in Jasta 27 and scored six victories over enemy fighters.
He was then given command of Jasta 40.
He downed an observation balloon while leading this squadron before being killed in action on 9 July 1918.