Reserve-Korps / XXXXI RK) was a corps level command of the German Army in World War I. XXXXI Reserve Corps was formed in December 1914.

[1] It was part of the second wave of new Corps formed in the early stages of World War I consisting of XXXVIII - XXXXI[2] Reserve Corps of 75th - 82nd Reserve Divisions (plus 8th Bavarian Reserve Division).

The personnel was predominantly made up of kriegsfreiwillige (wartime volunteers) who did not wait to be called up.

[4] On formation in December 1914, XXXXI Reserve Corps consisted of two divisions.

[5] but was weaker than an Active Corps In summary, XXXXI Reserve Corps mobilised with 18 infantry battalions, 2 cavalry detachments, 24 field artillery batteries (96 guns), 2 cyclist companies and 2 pioneer companies.