Reserve-Korps / XXIII RK) was a corps level command of the German Army in World War I. XXIII 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.

[3] On formation in October 1914, XXIII Reserve Corps consisted of two divisions.

[4] but was weaker than an Active Corps In summary, XXIII 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.

XXIII Reserve Corps had the following commanders during its existence:[13][14]