Reserve-Korps / XXVI RK) was a corps-level command of the German army during World War I. XXVI Reserve Corps was formed in October 1914.

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

[2] It was still in existence at the end of the war[3] in the 18th Army, Heeresgruppe Deutscher Kronprinz on the Western Front.

[4] On formation in October 1914, XXVI Reserve Corps consisted of two divisions.

[5] but was weaker than an Active Corps In summary, XXVI Reserve Corps mobilised with 26 infantry battalions, 8 machine gun platoons (16 machine guns), 2 cavalry detachments, 18 field artillery batteries (72 guns) and 2 pioneer companies.