Lajos Keresztes-Fischer (8 January 1884 – 29 April 1948) was a Hungarian military officer, who served as Chief of the General Staff in 1938.

He served for the Supreme Command of Miklós Horthy's National Army in 1919.

He became Chief of General Staff for several months when his predecessor Lieutenant-General Jenő Rátz was appointed Minister of Defence in the cabinet of Béla Imrédy.

During the first years of the Second World War he served as Adjutant-General of the Military Chancellery.

During the Arrow Cross Party's coup (15–16 October 1944) he was arrested and imprisoned in the Dachau concentration camp by the Gestapo along with his brother.