The term Reichskriegsflagge (German: [ˈʁaɪçsˌkʁiːksflaɡə], lit.'Imperial War Flag') refers to several war flags and war ensigns used by the German armed forces in history. A total of eight different designs were used in 1848–49 and between 1867–1871 and 1945.

German and Austrian war ensigns, including those called "Reichskriegsflagge"

Today the term refers usually to the flag from 1867–1871 to 1918, the war flag of Imperial Germany.