The Brazilian Marine Corps (Brazilian Portuguese: Corpo de Fuzileiros Navais, CFN; lit. 'Corps of Naval Fusiliers' or 'Corps of Naval Riflemen') is the Brazilian Navy's naval infantry component. Its operational components are the Fleet Marine Force (Força de Fuzileiros da Esquadra, FFE), under the Naval Operations Command, in Rio de Janeiro, and regional battalions under the Naval Districts in the coast and the Amazon and Platine basins. Its seagoing component is the FFE, with a core of three infantry battalions and its own artillery, amphibious and land armor, special operations forces and other support elements.

Tracing their origins to the Portuguese Navy's Royal Brigade of the Navy, Brazilian marines served across the 19th century aboard and landed from the Imperial Navy's ships. By the next century, they were relegated to guard duty and largely influenced by the Brazilian Army. In political struggles, they were usually loyalists. Only after 1950 did the CFN acquire true amphibious warfare capabilities, under long-lasting inspiration from the United States Marine Corps.

The CFN relies on the fleet and Naval Aviation for mobility. Its amphibious capability varies historically according to the fleet's available ships and attention given to other priorities, such as counterinsurgency during the military dictatorship and law and order in the current political order. Participation in United Nations peacekeeping is frequent and the 2008 Brazilian National Defense Strategy established that the Marine Corps must be a high-readiness expeditionary force for power projection by the navy. In Brazil's strategic surroundings, this means a capability for urban operations, from humanitarian aid to war, in crisis-ridden countries.

As a cadre of personnel, the Marine Corps is one of the navy's three main components, alongside the Fleet and Logistics Corps, and its ranks are named almost the same as the others. As officers, marines may rise to the highest peacetime rank. Marines are a professional, all-volunteer cadre which undergoes a cycle of military exercises with amphibious assaults (Operation Dragão) and live fire on land (Operation Formosa). They have a distinctive identity tied to both the sea and land and comparable to the army's infantry.

The Brazilian Marine Corps' official history dates back to the transfer of the Portuguese court to Brazil in 1807, making it the oldest force of marines in Latin America. The Anglo-Portuguese squadron that transported the court to Brazil also brought along the Portuguese Navy's Royal Marine Brigade (Brigada Real de Marinha), a corps of naval infantry. The corps, founded in 1797, was divided into infantry, artillery and engineer units and is the predecessor to the modern-day Portuguese Marine Corps. Earlier during the 17th century, Portuguese marines of the Terço da Armada da Coroa de Portugal had fought in Brazil against the invasions of the Dutch West India Company, conducting amphibious landings during the 1625 recapture of Bahia.

In April 1809, the Royal Marine Brigade participated in the Portuguese conquest of French Guiana, which the CFN considers to be its baptism of fire, even though the marines were Portuguese. 550 marines of the Brigade embarked on a four-ship Portuguese Navy squadron at Rio de Janeiro, which set sail for Cayenne and arrived there on 6 April. The marines landed on the beaches near Cayenne and advanced into the colony, which capitulated on 14 April. Upon returning to Rio, the marines were stationed at the Fortress of São José at Cobras Island, which is the modern-day headquarters of the CFN. The Royal Marine Brigade subsequently participated in the first Banda Oriental invasion, second Banda Oriental invasion and Pernambucan revolution.

When John VI of Portugal returned to Lisbon in 1821, he left a unit of the Royal Marine Brigade, the Battalion of Fusilier-Sailors (Batalhão de Fuzileiros-Marinheiros), in Rio. Serving under Pedro, Prince Regent, the unit fought for the Brazilians during the Brazilian War of Independence, carrying out amphibious landings and artillery bombardments against Portuguese forces.

Shortly after Brazil's independence in 1822, the Battalion of Fusilier-Sailors was renamed the Rio de Janeiro Artillery Battalion of the Navy (Batalhão de Artilharia da Marinha do Rio de Janeiro). In this early phase, the CFN was a naval artillery corps, later named Imperial Navy Artillery Brigade (Imperial Brigada de Artilharia de Marinha, 1826) and Navy Artillery Corps (Corpo de Artilharia de Marinha, 1827). This was one of the Imperial Brazilian Navy's cadres of personnel, alongside the Fleet Corps (Corpo da Armada), and the only properly militarized cadre. Its commander was an army artillery officer, who was also given command of the Fortress of São José. Military campaigns were largely maritime, owing to the difficulty of transport by land. Throughout the tumultuous regency period (1831–1840), the Navy Artillery Corps was deployed against internal revolts and was itself behind one of them, on 6 October 1831, leading to the bombing of Cobras Island by the fleet and its occupation by the army and National Guard.