Movimento dos Trabalhadores Rurais Sem Terra

Landless Workers' Movement (Portuguese: Movimento dos Trabalhadores Sem Terra, MST) is a social movement in Brazil, generally regarded as one of the largest in Latin America with an estimated informal membership of 1.5 million membership across 23 of Brazil's 26 states. MST defines its goals as access to the land for poor workers through land reform in Brazil and activism around social issues that make land ownership more difficult to achieve, such as unequal income distribution, racism, sexism, and media monopolies. MST strives to achieve a self-sustainable way of life for the rural poor.

The MST differs from previous land reform movements in its single-issue focus; land reform for them is a self-justifying cause. It says it is legally justified in occupying unproductive land, pointing to the most recent Constitution of Brazil (1988), which contains a passage saying that land should fulfill a social function. It also says, based on 1996 census statistics, that 3% of the population owns two-thirds of all arable land in Brazil.

Land reform has a long history in Brazil, and the concept pre-dates the MST. In the mid-20th century, Brazilian leftists reached a consensus that democratization and widespread actual exercise of political rights would require land reform. Brazilian political elites actively opposed land reform initiatives, which they felt threatened their social and political status. Therefore, political leaders of the rural poor attempted to achieve land reform from below, through grassroots action. MST broke new ground by tackling of land reform by itself, "breaking... dependent relations with parties, governments, and other institutions", and framing the issue in purely political terms rather than social, ethical or religious.

The first statute to regulate land ownership in Brazil after its independence, Law 601 or Lei de Terras (Landed Property Act), took effect September 18, 1850. A colonial administration based on Portuguese feudal law, considered property ownership to stem from royal grants (sesmarias) and pass through primogeniture (morgadio). In the independent Brazilian state, the default means of acquiring land was through purchase, from either the State or a previous private owner. This law strongly limited squatter's rights and favoured the historic concentration of land ownership which became a hallmark of modern Brazilian social history. The Lei de Terras left in place the colonial practice of favouring of large landholdings created by mammoth land grants to well-placed people, which were usually worked by slaves.