The Cuban Revolution of 1933, also called the Sergeants' Revolt, was a coup d'état that occurred in Cuba in September 1933. It began as a revolt of sergeants and enlisted men in the military, who soon allied with student activists in the Directorio Estudiantil Universitario. The coup deposed Carlos Manuel de Céspedes y Quesada as president, installing a new government led by a five-man coalition known as the Pentarchy of 1933. After only five days, the Pentarchy gave way to the presidency of Ramón Grau, whose term is known as the One Hundred Days Government. The leader of the revolt, Sergeant Fulgencio Batista, became the head of the armed forces and began a long period of influence on Cuban politics.

Background: The authoritarian policies of Gerardo Machado and the Great Depression, beginning in 1929, plunged Cuba into an economic and social crisis, during which opposition groups proliferated. Pressure and demonstrations by the Directorio Estudiantil Universitario (Student Directory), workers, and U.S. Ambassador Sumner Welles forced Machado to resign. Carlos Manuel de Céspedes y Quesada led a provisional government that included members of the opposition group ABC in its cabinet. Other elements of the Machado opposition were unsatisfied with the provisional government, which they saw as an unacceptable compromise with U.S. interventionism. On August 24, the Student Directory issued a Manifesto-Program that denounced the ABC and made various demands, including the formation of a new government.

After the fall of Machado, the military perceived its situation as precarious. Opposition forces controlled Havana and took revenge on supporters of the Machado regime, including police and some soldiers. The military was reluctant to intervene in this situation, lest the public perceive it as an agent of the old regime. The arrest of 50 soldiers and 21 officers did not satisfy demands for reform. Critics of the Céspedes government, including members of the military, charged that it was not taking sufficient action against Machado's backers within the armed forces and that it had failed to reinstate officers who had opposed Machado. This situation exacerbated longstanding tensions related to age, class, and race among the ranks of officers.

A group of sergeants began meeting at the Columbia barracks, forming the Columbia Military Union. Their ambition to improve conditions in the army quickly expanded into a plan for regime change. This group, later called the Junta of the Eight despite uncertainty about the number of members, included Batista and other members of his ABC cell, as well as Pablo Rodríguez, whom some perceived to be the group's leader. A funeral for Sergeant Miguel Ángel Hernández y Rodríguez, who had been captured and killed by the Machado government in May 1933, took place on 19 August 1933. This gave Batista the opportunity to deliver a passionate speech that brought him attention as a future leader. At the funeral he met journalist Sergio Carbó, who became an important contact in the civilian world. In August, the group of sergeants issued a manifesto calling for dignity, respect, and benefits for soldiers, and declaring their duty to rebel. Batista asked the ABC, of which he was a member, to publicize the manifesto. The ABC, having established itself as part of the status quo government, refused, and Batista and others left the group. Other factions within the military were also plotting against the Céspedes government, and some spoke openly against it. As the movement grew, the plotters met in larger venues, including the Masonic Gran Logia de Cuba and a military hospital. These preparations became somewhat obvious, but meetings continued under the pretext of planning projects to improve enlisted men's quality of life. The action mostly took place in Havana, with some outreach to Matanzas Province shortly before the coup. On September 3 and 4, some lower-ranking officers at Camp Columbia directly raised issues of back pay and promotions with senior officers. On September 4, Captain Mario Torres Menier appeared at a meeting of the enlisted men at Camp Columbia. Batista allowed him to enter. The soldiers made their complaints with mounting enthusiasm; Torres Menier withdrew to consult with other superior officers. Another meeting was scheduled for 8 p.m. In the interim, leaders of the coup rallied their supporters. Batista contacted Carbó and secured the support of Juan Blas Hernández, a rebel who had opposed Machado for two years. The meeting that evening took place in a theater. The senior officers had been excluded. Batista spoke from onstage, declaring, "From this moment forward, do not obey anyone's orders but mine. First sergeants must immediately take control of their respective military units. If there is no first sergeant, or if he refuses to take command, the senior sergeant must do so. If there is no sergeant, a corporal. If there is no willing corporal, then a soldier, and if not, then a recruit. The units must have someone in command, and he must be an enlisted man." Thus the sergeants took uncontested control of Columbia barracks and soon established communications with sympathetic officers in other cities. Members of the Student Directory—beginning with José Leyva, Ramiro Valdés Daussá, Juan António Rubio Padilla, Carlos Prío Socarrás, Rubén de León, and Justo Carrillo—came to the barracks and joined forces with the army. While President Céspedes was away from Havana to survey hurricane damage, the rebels forced the remaining government officers in Havana to leave their posts. They then issued a proclamation announcing that they were in control of the country and set up a pentarchy modeled on the then-current government of Uruguay. After President Céspedes returned on September 5, members of the junta arrived at his office and informed him that they were to receive the government from him. Swayed by their claim to command the allegiance of the military rank and file, Céspedes vacated the presidential palace. The junta of officers and students proclaimed that it had taken power to fulfill the aims of the revolution; it briefly described a program that included economic restructuring, punishment of wrongdoers, recognition of public debts, establishment of courts, political reorganization, and other actions necessary to construct a new Cuba based on justice and democracy. Both Grau and Batista visited Welles on September 5 to seek support from the United States and ascertain its position.