When the Franco-Prussian War erupted in 1870 von Kirchbach was promoted to General der Infanterie and appointed to command the Prussian V Corps. He played a prominent role in the early battles of the war at Wissembourg and Wörth. At Sedan von Kirchbach and his V Corps were tasked with closing the ring on the northern side around the French "Army of Châlons" trapped at Sedan. During the siege of Paris, V Corps occupied positions to the southwest of the city. Von Kirchbach was able to repel all French attempts to break through his positions at Mont Valerien. On 18 February 1871 he was given the oak leaves to his Pour le Mérite. In February 1871 V Corps was sent to Orléans and in March to Vesoul.