The Tito–Stalin split or the Soviet–Yugoslav split was the culmination of a conflict between the political leaderships of Yugoslavia and the Soviet Union, under Josip Broz Tito and Joseph Stalin, respectively, in the years following World War II. Although presented by both sides as an ideological dispute, the conflict was as much the product of a geopolitical struggle in the Balkans that also involved Albania, Bulgaria, and the communist insurgency in Greece, which Tito's Yugoslavia supported and the Soviet Union distanced itself from.

In the years following World War II, Yugoslavia pursued economic, internal, and foreign policy objectives that did not align with the interests of the Soviet Union and its Eastern Bloc allies. In particular, Yugoslavia hoped to admit neighbouring Albania to the Yugoslav federation. This fostered an atmosphere of insecurity within the Albanian political leadership and exacerbated tensions with the Soviet Union, which made efforts to impede Albanian–Yugoslav integration. Yugoslav support of the communist rebels in Greece against the wishes of the Soviet Union further complicated the political situation. Stalin tried to pressure Yugoslavia and moderate its policies using Bulgaria as an intermediary. When the conflict between Yugoslavia and the Soviet Union became public in 1948, it was portrayed as an ideological dispute to avoid the impression of a power struggle within the Eastern Bloc.

The split ushered in the Informbiro period of purges within the Communist Party of Yugoslavia. It was accompanied by a significant level of disruption to the Yugoslav economy, which had previously depended on the Eastern Bloc. The conflict also prompted fears of an impending Soviet invasion and even a coup attempt by senior Soviet-aligned military leaders, a fear fueled by thousands of border incidents and incursions orchestrated by the Soviets and their allies. Deprived of aid from the Soviet Union and the Eastern Bloc, Yugoslavia subsequently turned to the United States for economic and military assistance.

During World War II, the relationship between Yugoslav Partisan leader Josip Broz Tito and Soviet leader Joseph Stalin was complicated by the Soviet Union's alliances, Stalin's desire to expand the Soviet sphere of influence beyond the borders of the Soviet Union, and the confrontation between Tito's Communist Party of Yugoslavia (KPJ) and the Yugoslav government-in-exile headed by King Peter II of Yugoslavia.

The Axis powers invaded the Kingdom of Yugoslavia on 6 April 1941. The country surrendered 11 days later, and the government fled abroad, ultimately relocating to London. Nazi Germany, Fascist Italy, Bulgaria and Hungary annexed parts of the country. The remaining territory was broken up: most of it was organised as the Independent State of Croatia (NDH), a puppet state garrisoned by German and Italian forces, while the capital Belgrade remained in the German-occupied territory of Serbia. The Soviet Union, still honouring the Molotov–Ribbentrop Pact, broke off relations with the Yugoslav government and sought, through its intelligence assets, to set up a new Communist organisation independent of the KPJ in the NDH. The Soviet Union also tacitly approved the restructuring of the Bulgarian Workers' Party. In particular, the party's new organisational structure and territory of operation were adjusted to account for the annexation of Yugoslav territories by Bulgaria. The Soviets only reversed their support for such actions in September 1941—well after the start of the Axis invasion of the Soviet Union—after repeated protests from the KPJ.

In June 1941, Tito informed the Comintern and Stalin about his plans for an uprising against the Axis occupiers. However, Stalin considered the prolific use of Communist symbols by Tito's Partisans to be problematic. This was because Stalin viewed his alliance with the United Kingdom and the United States as necessarily contrary to the Axis destruction of "democratic liberties". Stalin thus felt that Communist forces in Axis-occupied Europe were actually obligated to fight to restore democratic liberties—even if temporarily. In terms of Yugoslavia, this meant that Stalin expected the KPJ to fight to restore the government-in-exile. Remnants of the Royal Yugoslav Army, led by Colonel Draža Mihailović and organised as Chetnik guerrillas, were already pursuing the restoration of the Yugoslav monarchy.

In October 1941, Tito met Mihailović twice to propose a joint struggle against the Axis. Tito offered him the position of chief of staff of the Partisan forces, but Mihailović turned down the offer. By the end of the month, Mihailović concluded that the Communists were the true enemy. At first, Mihailović's Chetniks fought the Partisans and the Axis simultaneously, but within months, they began collaborating with the Axis against the Partisans. By November, the Partisans were fighting the Chetniks while sending messages to Moscow protesting Soviet propaganda praising Mihailović.

In 1943, Tito transformed the Anti-Fascist Council for the National Liberation of Yugoslavia (AVNOJ) into an all-Yugoslav deliberative and legislative body, denounced the government-in-exile, and forbade King Peter's return to the country. These decisions ran against explicit Soviet advice instructing Tito not to antagonise the exiled monarch and his government. Stalin was at the Tehran Conference at the time and viewed the move as a betrayal of the Soviet Union. In 1944–1945, Stalin's renewed instructions to Communist leaders in Europe to establish coalitions with bourgeois politicians were met with incredulity in Yugoslavia. This shock was reinforced by Stalin's revelation of the Percentages Agreement to the surprised Edvard Kardelj, vice president of the Yugoslav provisional government. The agreement, concluded by Stalin and British Prime Minister Winston Churchill during the 1944 Moscow Conference divided Eastern European countries into British and Soviet spheres of influence—splitting Yugoslavia evenly between the two.