A machete (/məˈʃɛti/; Spanish pronunciation: [maˈtʃete]) is a broad blade used either as an agricultural implement similar to an axe, or in combat like a long-bladed knife. The blade is typically 30 to 66 centimetres (12 to 26 in) long and usually under 3 millimetres (1⁄8 in) thick. In the Spanish language, the word is possibly a diminutive form of the word macho, which was used to refer to sledgehammers. Alternatively, its origin may be machaera, the name given by the Greeks and Romans to the falcata. It is the origin of the English language equivalent term matchet, though this is rarely used. In much of the English-speaking Caribbean, such as Jamaica, Barbados, Guyana, Grenada, and Trinidad and Tobago, the term cutlass is used for these agricultural tools.

In various tropical and subtropical countries, the machete is frequently used to cut through rainforest undergrowth and for agricultural purposes (e.g. cutting sugar cane). Besides this, in Latin America a common use is for such household tasks as cutting large foodstuffs into pieces—much as a cleaver is used—or to perform crude cutting tasks, such as making simple wooden handles for other tools. It is common to see people using machetes for other jobs, such as splitting open coconuts, yard work, removing small branches and plants, chopping animals' food, and clearing bushes.

Machetes are often considered tools and used by adults. However, many hunter–gatherer societies and cultures surviving through subsistence agriculture begin teaching babies to use sharp tools, including machetes, before their first birthdays.

People in uprisings sometimes use these weapons. For example, the Boricua Popular Army are unofficially called macheteros because of the machete-wielding laborers of sugar cane fields of past Puerto Rico.

Many of the killings in the 1994 Rwandan genocide were performed with machetes, and they were the primary weapon used by the Interahamwe militias there. Machetes were also a distinctive tool and weapon of the Haitian Tonton Macoute.

In 1762, the British captured Havana in a lengthy siege during the Seven Years' War. Volunteer militiamen led by Pepe Antonio, a Guanabacoa councilman, were issued with machetes during the unsuccessful defense of the city. The machete was also the most iconic weapon during the independence wars in Cuba, although it saw limited battlefield use. Carlos Manuel de Céspedes, owner of the sugar refinery La Demajagua near Manzanillo, freed his slaves on 10 October 1868. He proceeded to lead them, armed with machetes, in revolt against the Spanish government. The first cavalry charge using machetes as the primary weapon was carried out on 4 November 1868 by Máximo Gómez, a sergeant born in the Dominican Republic, who later became the general in chief of the Cuban Army.

The machete is a common side arm and tool for many ethnic groups in West Africa. Machetes in this role are referenced in Chinua Achebe's Things Fall Apart.

Some countries have a name for the blow of a machete; the Spanish machetazo is sometimes used in English. In the British Virgin Islands, Grenada, Jamaica, Saint Kitts and Nevis, Barbados, Saint Lucia, and Trinidad and Tobago, the word planass means to hit someone with the flat of the blade of a machete or cutlass. To strike with the sharpened edge is to "chop". Throughout the English-speaking islands of the Caribbean, the term "cutlass" refers to a laborers' cutting tool.