The Nicaraguan Revolution (Spanish: Revolución nicaragüense), or Sandinista Revolution (Spanish: Revolución popular sandinista) was an armed conflict that took place in the Central American country of Nicaragua from 1978 to 1990.

It began with rising opposition to the Somoza dictatorship in the 1960s and 1970s, the overthrow of the dictatorship in 1978–1979, and fighting between the government and the Contras from 1981 to 1990. The revolution revealed the country as one of the major proxy war battlegrounds of the Cold War.

The initial overthrow of the Somoza dictatorial regime in 1978–79 cost many lives, and the Contra War of the 1980s took tens of thousands more and was the subject of fierce international debate. Because of the political turmoil, failing economy, and limited government influence, during the 1980s both the FSLN (a left-wing collection of political parties) and the Contras (a right-wing collection of counter-revolutionary groups) had to receive aid from the Soviet Union and the United States, respectively.

A peace process started with the Sapoá Accords in 1988 and the Contra War ended after the signing of the Tela Accord in 1989 and the demobilization of the FSLN and Contra armies. A second election in 1990 resulted in the election of the UNO, and the Sandinistas lost power until 2006.

Following the United States occupation of Nicaragua from 1912 to 1933 during the Banana Wars, a hereditary military dictatorship led by Somoza family took power, and ruled from 1937 until its collapse in 1979. The Somoza dynasty consisted of Anastasio Somoza García, his eldest son Luis Somoza Debayle, and finally Anastasio Somoza Debayle. The Somoza era was characterized by economic development, albeit with rising inequality and political corruption, strong US support for the government and its military, as well as a reliance on US-based multinational corporations.

In 1961, Carlos Fonseca Amador, Silvio Mayorga, and Tomás Borge Martínez formed the Sandinista National Liberation Front (FSLN) with other student activists at the Universidad Nacional Autonoma de Nicaragua (UNAN) in Managua. The founders were experienced activists. Amador, first General Secretary, had worked with others on a newspaper "broadly critical" of the Somoza family titled Segovia.

Consisting of approximately 20 members during the 1960s, with the help of students, FSLN gathered support from peasants and anti-Somoza elements, as well as from the communist Cuban government, the socialist Panamanian government of Omar Torrijos, and the social democratic Venezuelan government of Carlos Andrés Pérez.

By the 1970s the coalition of students, farmers, businesses, churches, and a small percentage of Marxists was strong enough to launch a military effort against the regime of Anastasio Somoza Debayle. The FSLN focused on guerrilla tactics, inspired by Fidel Castro and Ché Guevara. They launched an unsuccessful campaign in 1963 known as the Raití-Bocay campaign in rural, northern Jinotega Department, where "when guerrillas did encounter the National Guard, they had to retreat...with heavy losses." Further operations included a devastating loss near the city of Matagalpa, during which Mayorga was killed. During this time, FSLN reduced attacks, instead focusing on solidifying the organization.