RENAMO (from the Portuguese Resistência Nacional Moçambicana, lit. 'Mozambican National Resistance') is a Mozambican political party and militant group. The party was founded with the active sponsorship of the Rhodesian Central Intelligence Organisation (CIO) in May 1977 from anti-communist dissidents opposed to Mozambique's ruling FRELIMO party. RENAMO was initially led by André Matsangaissa, a former senior official in FRELIMO's armed wing, and was composed of several anti-communist dissident groups which appeared immediately prior to, and shortly following, Mozambican independence. Matsangaissa, who died in 1979, was succeeded by Afonso Dhlakama, who led the organization until he died in 2018. He was succeeded by Ossufo Momade.

Critics of RENAMO frequently described the movement as a proxy of Rhodesia and South Africa's apartheid government. It has been theorised that RENAMO was formed for the sole purpose of countering FRELIMO support for the Zimbabwe African National Liberation Army (ZANLA). On the other hand, RENAMO was also reflective of FRELIMO's own splintering support base and dwindling popularity in the immediate post-independence era. Its political programme centered around the abandonment of FRELIMO's socialist policies, the adoption of a free market economy, and more traditionalist concerns such as the reinstatement of tribal leaders to positions of authority. RENAMO's ranks included a number of Mozambican political exiles who genuinely opposed FRELIMO on principle, including FRELIMO defectors disillusioned with its Marxist–Leninist ideology, but also large numbers of recruits conscripted by force.

With Rhodesian support, RENAMO commenced an insurgency against the FRELIMO government in 1977, sparking the Mozambican Civil War. The war was characterised by severe human rights violations on both sides and crippled the already debilitated Mozambican economy. RENAMO and FRELIMO acceded to the Rome General Peace Accords in October 1992, which ended FRELIMO's one-party state and introduced multi-party democratic elections. In return, RENAMO pledged to abandon its armed struggle and conduct its future activities by political means within the framework of the new electoral system. Following the end of the war, RENAMO was responsible for promoting constitutional reforms as well as the promotion of a strong domestic private sector.

Renewed clashes broke out between RENAMO's militant forces and the FRELIMO government in 2013. RENAMO resumed its insurgency, citing state corruption and electoral fraud perpetuated by FRELIMO officials. A second peace agreement was reached between RENAMO and FRELIMO in August 2019, resulting in the virtual end of the insurgency. A RENAMO splinter group known as the RENAMO Military Junta (RMJ) was quickly formed from party dissidents opposed to the peace process; the RMJ continued to carry out minor guerrilla operations until December 2021, when the last of its members surrendered to Mozambican security forces.

From the early 1960s to the mid-1970s, Portugal fought a series of bitter counter-insurgency conflicts against independence movements in its three primary African colonies—Angola, Mozambique, and Guinea-Bissau. In Mozambique, the armed struggle against colonial rule was spearheaded by the Front for the Liberation of Mozambique (FRELIMO), which was initially formed in exile in neighbouring Tanzania. FRELIMO recruited from Mozambican migrant workers and intellectuals living abroad, where they had been exposed to the emerging popularity of anti-colonial and nationalist causes overseas. Its political programme was anti-colonial, but also anti-traditionalist; FRELIMO leaders planned to wrest social and political power from the Portuguese administration, as well as on the grassroots level from local tribal authorities. The party also envisioned a radical restructuring of post-colonial Mozambican society in accordance with the principles of scientific socialism. In September 1964, FRELIMO initiated an armed insurgency. Its decision to take up arms was influenced by a number of internal and external factors, namely the recent successes of indigenous anti-colonial guerrilla movements in French Indochina and French Algeria, as well as encouragement from contemporary African statesmen such as Ahmed Ben Bella, Gamal Abdel Nasser, and Julius Nyerere. FRELIMO insurgents initially received training primarily in North Africa and the Middle East in countries such as Algeria, with the Soviet Union and People's Republic of China providing military equipment. FRELIMO established a permanent foothold in underdeveloped northern Mozambique and began expanding its operations southwards, reaching the central provinces by 1973. Portugal responded with increasingly large scale search and destroy operations and strengthening military and intelligence ties to the neighbouring states of Rhodesia and South Africa, then ruled by white minority governments sympathetic to the colonial regime. FRELIMO, in turn, forged an informal alliance with a Rhodesian insurgent movement, the Zimbabwe African National Liberation Army (ZANLA). ZANLA insurgents were permitted to infiltrate Rhodesian territory from FRELIMO-held areas of Mozambique, inexorably linking the Mozambican conflict to the Rhodesian Bush War.

The 1974 Carnation Revolution and the collapse of Portugal's right-wing Estado Novo government plunged Lisbon into turmoil and brought to power a military junta known as the Armed Forces Movement. The Portuguese junta was committed to divesting itself of the colonies and ending the increasingly costly African wars. The resulting confusion among the metropole's military forces in Mozambique allowed FRELIMO to wrest control of large sections of the territory from the Portuguese. In the absence of Portuguese repression, a number of new Mozambican political parties, including some formed by FRELIMO splinter factions, appeared and began campaigning for support. Portugal announced it would initiate a political transition in Mozambique simultaneously with multi-party elections prior to independence, but FRELIMO condemned the proposal. The party's leadership, headed by Samora Machel, countered that it was the sole legitimate representative of the Mozambican people, and demanded it be permitted to take power directly, without multi-party elections. In early September 1974, Portugal announced it would comply with FRELIMO's request. Portuguese officials promised that after nine months, the positions of local government would be handed to FRELIMO appointees, and no elections would be held.

The decision to effect a direct transfer of power to FRELIMO, without a local referendum or elections, was greeted with trepidation by South Africa and Rhodesia. It also resulted in an exodus of Portuguese settlers, FRELIMO dissidents, and indigenous troops who had served with Portuguese auxiliary units, including the elite Flechas, fearing retribution under the new regime. Many of the new exiles fled to Rhodesia, where they were recruited as assets by the Rhodesian Central Intelligence Organisation (CIO). The most prominent anti-FRELIMO exile in Rhodesia was Orlando Cristina, a former member of the colonial security services in Mozambique who had served as a regional liaison with the Rhodesian government. Cristina set up a Portuguese-language radio broadcasting station, known as Voz da Africa Livre, which broadcast anti-communist and anti-FRELIMO messages into Mozambique. Cristina's broadcasts called attention to human rights violations committed by FRELIMO, including the detention of party dissidents, and accused FRELIMO of betraying Mozambican nationalism by pandering to the Marxist ideology of the Soviet Union. The CIO hoped to use Voz da Africa Livre to recruit disaffected Mozambicans for an anti-FRELIMO paramilitary force. One such recruit was André Matsangaissa, a former FRELIMO official who had been imprisoned by the party in a re-education camp following the transfer of power; Matsangaissa had subsequently escaped to Rhodesia and was familiar with Cristina's broadcasts. Matsangaissa met with Cristina and argued that hostile radio messages alone could not change the political situation in Mozambique; armed struggle was necessary. Shortly thereafter, the CIO recruited Matsangaissa as the leader for its new anti-FRELIMO force. The militants received guerrilla training from the CIO and were infiltrated back into Mozambique, where they conducted surveillance of ZANLA movements at the Rhodesians' behest. In February 1977, the unit demonstrated its ability to carry out autonomous operations when it stormed a FRELIMO re-education camp in Sofala Province, freeing the detainees there. During a meeting at Cristina's home in May 1977, the unit's leadership formally adopted the title Resistência Nacional Moçambicana (RENAMO).

RENAMO unified with another rebel group, the Revolutionary Party of Mozambique (PRM) in 1982. As a result of this merger, the rebel group was able to expand its operations in northern Mozambique, particularly in Zambezia Province. In 1984 the South African and Mozambican governments signed the Nkomati Accord, in which the South African National Party minority regime promised to stop sponsoring RENAMO operations if the Mozambican government expelled exiled members of the African National Congress (ANC) residing there. This was consistent with the Total National Strategy pursued by the National Party regime, utilizing threats of military reprisals to force Mozambique into subjugation under the Afrikaner nationalists hegemonial ambitions in the region. In 1988, RENAMO experienced its only major split during the civil war, when former PRM commander Gimo Phiri broke off and founded an independent insurgent group known as Mozambican National Union (UNAMO).