On July 5, 1943, German forces launch Operation Citadel (Unternehmen Zitadelle), beginning the Battle of Kursk. The plan was to utilize armored forces to conduct a double envelopment of Soviet forces along the Kursk salient and thus cut them off from resupply and reinforcement. However, German forces were greatly outnumbered by the Soviets and especially lacking in infantry, vital for holding the ground taken by the offensive. The German offensive was initially met with success in along both the northern and southern fronts; however, stubborn Soviet defenses and greater Soviet numbers ground the German advance to a halt. By July 11, the northern advance had been stopped. Meanwhile, a German breakthrough in the south was halted by a Soviet counter-offensive in the Battle of Prohkorovka.

On July 12, Hitler ordered the cancellation of Citadel due to the recent Allied landings in Sicily and orders part of the German forces on the Eastern Front diverted to Italy. On the same day, Operation Kutuzov was launched by the Soviets to the north of the Kursk salient and forced the Germans to commit reserved earmarked for the Kursk offensive to defend the German position around Orel. On August 3, Operation Rumyantsev is launched in the south and rapidly advances through the thin and weakened German defenses, reaching the city of Kharkov on August 12 and liberating the city by August 23. The Battle of Kursk drew to a close with an overwhelming Soviet victory.

The German military would never again be able to mount a major offensive against the Soviets on the Eastern Front for the remainder of the war. The Soviet Union was now fully on the offensive. The Germans were also now facing a second front in Italy due to the recent Allied landings and would see their forces and resourced further divided with the Allied invasion of France the following year.