The Rheinwiesenlager were a group of 19 concentration camps built in the Allied-occupied part of Germany by the U.S. Army to hold captured German soldiers at the close of the Second World War. Officially named Prisoner of War Temporary Enclosures (PWTE), they held between one and almost two million surrendered Wehrmacht personnel from April until September 1945.

More than 2.8 million German soldiers surrendered on the Western Front between D-Day and the end of April 1945; 1.3 million between D-Day and March 31, 1945; and 1.5 million of them in the month of April. From early March, these surrenders seriously weakened the Wehrmacht in the West, and made further surrenders more likely, thus having a snowballing effect. On March 27, Dwight D. Eisenhower declared at a press conference that the enemy were a whipped army. In March, the daily rate of POWs taken on the Western Front was 10,000; in the first 14 days of April it rose to 39,000, and in the last 16 days the average peaked at 59,000 soldiers captured each day. The number of prisoners taken in the West in March and April was over 1,800,000, more than double the 800,000 German soldiers who surrendered to the Russians in the last three or four months of the war. One reason for this huge difference, possibly the most important, was that German forces facing the Red Army tended to fight to the end for fear of Soviet captivity whereas German forces facing the Western Allies tended to surrender without putting up much if any resistance. Accordingly, the number of Germans killed and wounded was much higher in the East than in the West.