The 'Moravia-Ostrava Offensive Operation' was a Soviet undertaking to take the eastern part of the present-day Czech Republic (10 March/6 May 1945).

In the spring of 1945, the front line on the south-western border of Lesser Poland ran from Wieliczka via Jaworzno and Gliwice to Międzylesie. In this area the 4^th Ukrainian Front of General Polkovnik Ivan Ye. Petrov and the right wing of the 2^nd Ukrainian Front of Marshal Sovetskogo Soyuza Rodion Ya. Malinovsky were still somewhat farther to the east of the other Soviet fronts as they pushed to the west. On the western part of the High Tatra mountains, a curved front had come into being along the north-eastern and south-eastern borders of Slovakia. The 4^th Ukrainian Front, located in front of the western ridge of the Carpathian mountains and between Dukla and Kaschau, had 317,300 men, 184 tanks and self-propelled guns, 2,900 pieces of artillery and 416 aircraft in the first days of March 1945. The opposing German force was Generaloberst Gotthard Heinrici’s Armeegruppe 'Heinrici' comprising his own (from 19 March General Walter Nehring’s) 1^st Panzerarmee and Vezérezredes Dezsöo László's Hungarian 1^st Army with more than 150,000 men, 100 armoured fighting vehicles, 1,500 pieces of artillery and 120 aircraft.

On 10 March, the 4^th Ukrainian Front began its offensive with General Polkovnik Kirill S. Moskalenko’s 38^th Army from the area of Pszczyna and Černá Voda. The Soviet army was able to advance only between 1.85 and 2.5 miles (3 to 4 km) on the first day of its attack. By the evening of 17 March the Soviet army had pushed German defence back between 5/6 and 11 miles (9 and 12 km) on a front 9.33-mile (15-km) wide. The 38^th Army had still not reached the Soviet operational targets, but had suffered very considerable losses. When the offensive of General Polkovnik Pavel A. Korochkin’s 60^th Army of the 1^st Ukrainian Front against General Rudolf Bünau’s (from 6 April General Friedrich Wiese’s) XI Corps near Racibórz was successful, the Soviet switched the focus of their undertaking to their right wing.

On 24 March, the 4^th Ukrainian Front began the revised offensive. The northern industrial area of Moravia was now attacked from simultaneously from the north and east. The 38^th Army attacked Generalleutnant Ernest Sieler’s LIX Corps from the area of Żory, smashed through the German defences and took an area of 12.5 miles (20 km) wide and 4.35 miles (7 km) deep. A rapid counterattack by Generalmajor Heinrich-Georg Hax’s 8^th Panzerdivision and Generalmajor Hans-Joachim Deckert’s 19^th Panzerdivision failed to restore the situation. On 26 March, the positions at Wodzisław Śląski fell to the Soviets, and the formations of the 60^th Army and General Polkovnik Andrei A. Grechko’s 1^st Guard Army were able to advance toward Bohumín.

Eremenko, appointed as the new commander of the 4^th Ukrainian Front on 26 March, ordered the 38^th Army to attack once again on 27 March. This formation was then able to penetrate another 3.1 miles (5 km) and get within 1.25 and 1.85 miles (2 and 3 km) of the Oder river at Bukau. On 2 April, the LXXXXV Corps and CXXV Corps managed to cross the Oder river and create a bridgehead. At the same time, the XI Corps crossed the river at Tworków. In the east, General Leytenant Anton I. Gastilovich’s 18^th Army was able to overcome the Axis positions in the Tatra mountains and take Ruzomberok. Until 5 April, however, the progress of the 1^st Guards Army and the 18^th Army toward Frankstadt, which has now been extended to a depth of 12.5 miles (20 km,) could not be extended in the face of stiffening German resistance. On 6 April, Kurochkin’s 60^th Army, which up to this time had been part of the 1^st Ukrainian Front, was placed under the command of the 4^th Ukrainian Front. General Leytenant Ludvík Svoboda’s (from 3 April General Leytenant Karel Klapálek’s) I Czechoslovak Corps was transferred to Gastilovich’s 18^th Army and distinguished itself on 4 April by the liberation of Liptovský Mikulás.

The Stavka then changed the axis of continued operations to the south-west toward Olomouc as this offered the possibility of cutting off the 1^st Panzerarmee. The initial object of the revised Soviet offensive was now to cut the connection of the 1^st Panzerarmee with General Friedrich Schulz’s 17^th Army. Generalfeldmarschall Ferdinand Schörner moved five German divisions of this Heeresgruppe 'Mitte' to reinforce the threatened positions of the 1^st Panzerarmee in the Opava area.

On 22 April, Opava fell to the 60^th Army and on 30 April Ostrava fell into the hands of the 38^th Army, making the positions of General Karl von Le Suire’s XLIX Gebirgskorps (General Siegfried Rasp’s 78^th Division, Generalmajor Otto Schell’s 320^th Division, Generalleutnant Paul Klatt’s 3^rd Gebirgsdivision and Generalleutnant Friedrich Breith’s 4^th Gebirgsdivision) no longer tenable. General Leytenant Nikifor V. Medvedev’s XVII Guard Corps of the 18^th Army, which is still waiting in the east, was finally able to force Generalleutnant Werner Schmidt-Hammer’s LXXII Corps to retreat from the northern Váh section and occupy Zilina on 30 April. The 1^st Panzerarmee immediately began to retreat in the direction of Olomouc in order to avoid encirclement. On 6 May, Sternberk and the approaches to Olomouc fell into Soviet hands.

Thus Soviet forces were now in occupation of the Moravian Ostrava industrial area and had so created the conditions for the advance into the central areas of Czechoslovakia.

The Soviets lost 112,620 men (23,960 killed and 88,660 wounded) in the course of this offensive. Soviet claims for the German losses are considerably exaggerated.