Willy Marienfeld (1 October 1895 – 7 June 1944) was a highly decorated Oberstleutnant der Reserves in the Wehrmacht during World War II. He was also a recipient of the Knight's Cross of the Iron Cross with Oak Leaves. The Knight's Cross of the Iron Cross and its higher grade Oak Leaves was awarded to recognise extreme battlefield bravery or successful military leadership. Willy Marienfeld died from wounds on 7 June 1944 in Constanţa, Romania.