The Axis order of battle for the invasion of Yugoslavia was made up of the various operational formations of the German Wehrmacht and Waffen-SS, Italian Armed Forces and Hungarian Armed Forces that participated in the invasion of Yugoslavia during World War II, commencing on 6 April 1941. It involved the German 2nd Army, with elements of the 12th Army and a panzer group combined with overwhelming Luftwaffe (German Air Force) support. The eighteen German divisions included five panzer divisions, two motorised infantry divisions and two mountain divisions. The German force also included two well-equipped independent motorised regiments and was supported by over 800 aircraft. The Italian 2nd Army and 9th Army committed a total of 22 divisions, and the Royal Italian Air Force () had over 650 aircraft available to support the invasion. The Hungarian 3rd Army also participated, with support from the Royal Hungarian Air Force (, MKHL).
The Axis ground forces had effectively surrounded the Kingdom of Yugoslavia before the invasion began. The German 2nd Army, consisting of one motorised, one mountain, and two infantry corps was concentrated in southwestern Hungary and southeastern Austria, poised to drive south and east. One motorised corps of the German 12th Army was assembled near Sofia, Bulgaria, along with one motorised corps of the First Panzer Group, and these formations were assigned the task of striking the strongest Yugoslav formations stationed along the eastern border of the country. A further motorised corps was deployed near Timișoara in western Romania, ready to thrust south into the Banat region. The Italian 2nd Army, consisting of one fast () corps, one motorised corps and three infantry corps was assembled in northeastern Italy, with the task of driving southeast down the Dalmatian coast. The Italian 9th Army, comprising two corps and a sector defence command, was stationed in occupied northern Albania, and its stance was largely defensive. The Hungarian 3rd Army was concentrated along the Yugoslav border largely between the Danube and the Tisza, with the objective of seizing the Bačka and Baranja regions.
German, Italian and Hungarian air support was concentrated in Austria, Italy, southern Hungary, southern Romania, western Bulgaria and Albania. In total, over 1,500 Axis aircraft were available to support the invasion. Naval forces were limited to a few destroyers of the Royal Italian Navy () operating in the Adriatic Sea.
German
German land forces
The German formations committed to the invasion of Yugoslavia included over 337,000 men, and more than 2,000 mortars, 1,500 artillery pieces, 1,100 anti-tank guns, 875 tanks, and 740 other armoured fighting vehicles. The German land forces were under the overall direction of the commander of the German Army Generalfeldmarschall (Field Marshal) Walther von Brauchitsch.
2nd Army
The German 2nd Army was commanded by Generaloberst (General) Maximilian von Weichs, consisted of one motorised, one mountain, and two infantry corps, and was assembled in southwestern Hungary and southeastern Austria. The LII Infantry Corps suffered significant delays in deploying to its assembly area and was initially held in reserve. According to Schreiber, Stegemann and Vogel, three panzer divisions, four infantry divisions and one motorised infantry division were planned as reserves for the 2nd Army, but they did not participate in the fighting in Yugoslavia. According to Niehorster, these divisions were held as theatre reserves or were allocated to various formations. 2nd Army was supported by three bridging battalions and a road construction battalion.
XXXXVI Motorised Corps was supported by three motorised heavy artillery battalions, a motorised pioneer battalion, a road construction battalion, six bridging columns, and two Luftwaffe anti-aircraft battalions. XXXXIX Mountain Corps included two motorised heavy artillery battalions and a road construction battalion. LI Infantry Corps included seven motorised heavy artillery battalions, two assault gun battalions, two motorised pioneer battalions, two bridging battalions, two road construction battalions, and twelve bridging columns.
12th Army
The German 12th Army was commanded by Generalfeldmarschall Wilhelm List, and consisted of one mountain, three infantry and two motorised corps. Most of the 12th Army was deployed along the Bulgarian-Greek border in preparation for the invasion of Greece, and of the corps commanded by List, only the two motorised corps were committed to the invasion of Yugoslavia. For the first phase of the invasion of Yugoslavia, the First Panzer Group was also assigned to the 12th Army.