The Voronezh Front, commanded by Nikolai Vatutin, was tasked with defending the southern face of the salient. The Central Front, commanded by Konstantin Rokossovsky, defended the northern face. Waiting in reserve was the Steppe Front, commanded by Ivan Konev.
In February 1943 the Central Front had been reconstructed from the Don Front, which had been part of the northern pincer of Operation Uranus, responsible for the destruction of the 6th Army in the Stalingrad pocket.The Central and Voronezh Fronts each constructed three main defensive belts in their sectors, with each subdivided into several zones of fortification. The Soviets availed themselves of the labour of over 300,000 civilians. Fortifying each echelon was an interconnected web of minefields, barbed-wire fences, anti-tank ditches, deep entrenchments for infantry, anti-tank obstacles, dug-in armoured vehicles, and machine gun bunkers. Behind the three main defensive belts were three more belts prepared as fallback positions; the first was not fully occupied or heavily fortified, and the last two, though sufficiently fortified, were mostly not occupied. The combined depth of the three main defensive zones was about 40 kilometres (25 mi). The six defensive belts on either side of Kursk were 130–150 kilometres (81–93 mi). If the Germans managed to break through these defences they would still be confronted by additional defensive belts to the east, manned by the Steppe Front. These brought the total depth of the defences to nearly 300 kilometres (190 mi).
Red Army combat engineers laid 503,663 anti-tank mines and 439,348 anti-personnel mines, with the highest concentration in the first main defensive belt. More than 4,800 kilometres (3,000 mi) of trenches were dug, laid out in criss-cross pattern for ease of movement The minefields at Kursk achieved densities of 1,700 anti-personnel and 1,500 anti-tank mines per kilometre, about four times the density used in the defence of Moscow. The 6th Guards Army of the Voronezh Front, spread out over nearly 64 kilometres (40 mi) of front, was protected by 69,688 anti-tank and 64,430 anti-personnel mines in its first defensive belt and another 20,200 anti-tank and 9,097 anti-personnel mines in its second defensive belt.
Mobile obstacle detachments were tasked with laying more mines directly in the path of advancing armoured formations. These units, consisting of two platoons of combat engineers with mines at division level and one company of combat engineers normally equipped with 500–700 mines at corps level, functioned as anti-tank reserves at every level of command.[
In his letter of 8 April, Zhukov warned that the Germans would attack the salient with a strong armoured force: We can expect the enemy to put [the] greatest reliance in this year's offensive operations on his tank divisions and air force, since his infantry appears to be far less prepared for offensive operations than last year…. In view of this threat, we should strengthen the anti-tank defences of the Central and Voronezh fronts, and assemble as soon as possible.
Nearly all artillery, including howitzers, guns, anti-aircraft and rockets, were tasked with anti-tank defence. Dug-in tanks and self-propelled guns further strengthened the anti-tank defences. Anti-tank forces were incorporated into every level of command mostly as anti-tank strong points, with the majority concentrated on likely attack routes and the remainder amply spread out in elsewhere. Each anti-tank strong point typically consisted of four to six anti-tank guns, six to nine anti-tank rifles, and five to seven heavy and light machine guns. They were supported by mobile obstacle detachments as well as infantry with automatic weapons. Independent tank and self-propelled gun brigades and regiments were tasked with cooperating with the infantry during counterattacks.
Soviet preparations included increased activity of partisans, who attacked on German communications and supply lines. For June 1943 alone, in the occupied area behind Army Group Centre, 298 locomotives, 1,222 rail wagons, and 44 bridges were destroyed by partisans, while in the Kursk sector there were 1,092 partisan attacks against railways. Many of these attacks were coordinated through the Central Partisan Headquarters. Soviet Air Forces flew in supplies and provided communication and sometimes even air support for major undertakings.
Special training was provided to the infantry manning the defences to help them overcome the tank phobia that had been evident since the German invasion. Soldiers were packed into trenches and tanks were driven overhead until all signs of fear were gone. In combat the soldiers would spring up in the midst of the attacking infantry to separate them from the spearheading armoured vehicles, which could then be disabled or destroyed at point-blank range. Due to their lack of secondary armament like machine guns, this tactic would be successfully used against Ferdinand tanks. Once they were isolated from their supporting infantry they became vulnerable to infantry armed with anti-tank rifles, demolition charges, and Molotov cocktails.
The Soviets employed a number of maskirovka (deception techniques) to mask defensive positions and troop dispositions and to conceal the movement of men and materiel. These included camouflaging gun emplacements, constructing dummy airfields and depots, generating false radio traffic, and spreading rumours among the Soviet front line troops and the civilian population in the German-held areas. Movement of forces and supplies to and from the salient was carried out only at night. Ammunition caches were carefully concealed to blend in with the landscape. Radio transmission was restricted and fires were forbidden. Command posts were hidden and motor transportation in and around them were forbidden…. Without including the deeper reserves organised under the Steppe Front, the Soviets had massed about 1,300,000 men, 3,600 tanks, 20,000 artillery pieces, and 2,792 aircraft to defend the salient. This amounted to 26 per cent of the total manpower of the Red Army, 26 per cent of its mortars and artillery, 35 per cent of its aircraft, and 46 per cent of its tanks.