The 31st Division (31. Division) was a unit of the Prussian/German Army. It was formed on March 20, 1871, and was headquartered in Straßburg (now Strasbourg, France) until 1912, and then in Saarbrücken. The division was subordinated in peacetime to the XV Army Corps (XV. Armeekorps) until 1912, and then to the XXI Army Corps (XXI. Armeekorps). The division was disbanded in 1919 during the demobilization of the German Army after World War I. The division was recruited primarily in the southern part of the Rhine Province, but during World War I also drew replacements from Westphalia.