The Hungarian Second Army (Második Magyar Hadsereg) was one of three field armies raised by the Kingdom of Hungary which saw action during World War II. All three armies were formed on March 1, 1940. The Second Army was the best-equipped Hungarian formation at the beginning of the war, but was virtually eliminated as an effective fighting unit by overwhelming Soviet force during the Battle of Stalingrad, suffering 84% casualties. Towards the end of the war, a reformed Second Army fought more successfully at the Battle of Debrecen, but, during the ensuing Siege of Budapest, it was destroyed completely and absorbed into the Hungarian Third Army.

The Kingdom of Hungary was a reluctant member of the Axis at the beginning of the European conflict. Hungary's head of state was Regent Admiral Miklós Horthy and the government was led by Prime Minister Pál Teleki. On April 3, 1941, Teleki committed suicide when it became clear that Hungary was to take part in the invasion of Yugoslavia, its erstwhile ally.

The comparatively small Hungarian Army had a peacetime strength of only 80,000 men. Militarily, the nation was divided into seven corps commands. Each army corps consisted of three infantry divisions, each of which comprised three infantry regiments and an artillery regiment. Each corps also included two cavalry-brigades, two motorized infantry brigades, an anti-aircraft battery, a signals company, and a cavalry reconnaissance troop. On March 11, 1940, the Hungarian Army was expanded to three field armies, each with three corps. All three of these field armies were to see action against the Red Army before the end of the war.

Hungary did not immediately participate in Operation Barbarossa, the German invasion of the Soviet Union. Adolf Hitler did not directly ask for, nor necessarily want, Hungarian assistance at that time. Most of the Hungarian forces, including the three field armies, were initially relegated to duties within the reenlarged Hungarian state. Hungary regained substantial portions of its territories that had been ceded following the loss of World War I and the resultant Treaty of Trianon.

At the end of June 1941, Germany summoned Hungary to join in the attack on the Soviet Union. Hungary continued to resist joining in the war. The matter was settled on June 26, 1941, when the Soviet air force bombed Košice (Kassa) .

The Kingdom of Hungary declared war on the Soviet Union the next day, June 27, 1941. At first, only Hungary's "Karpat Group" with its integral "Rapid Corps" (Gyorshadtest) was sent to the Eastern Front, in support of the German 17th Army. Towards the end of 1941, only the exhausted and battle weary "Rapid Corps" was left. But, before Horthy would gain Hitler's consent to withdraw the "Rapid Corps," he had to agree to deploy an even larger Hungarian force.

Of the three Hungarian field armies, high command decided to send the Second Army. (The First Army was considered to be the "best" and the Third Army was still being organized). However the Armed Forces in general were so poorly equipped that practically all "modern" equipment (which was still dated by contemporary standards) was provided to the 2nd Army. Even after these desperate measures, the Second Army still lacked adequate motorized transport and especially anti-tank weapons. Germany had promised to provide the necessary equipment, but failed to deliver any meaningful quantities.

Practically all the armored troops Hungary had were re-organized into the 1st Hungarian Armored Division and attached to the Second Army. Similarly, almost all combat-worthy aircraft and supporting units were organized into the 1st Flight Group, also attached to the Second Army. For both the armored and air units, shortages in supplies and equipment caused significant delays, and they were deployed significantly later than infantry units.