Lei Áurea ("Golden Law") was the law that finally abolished slavery in Brazil, passed on May 13, 1888. It was preceded by the Lei do Ventre Livre ("Law of Free Birth" or "Womb"), of September 28, 1871, which freed all children born to slave parents. Both laws had been sanctioned by Isabel , Imperial Princess Regent of Brazil (1846-1921), who was regent at the time, her father, Emperor Dom Pedro II, being in Europe. For the second she was awarded the "Golden Rose" medal by Pope Leo XIII.

There were a number of reasons for the signing of the law, aside from the activities of abolitionists. Slavery was no longer profitable, with the wages of European immigrants, whose work conditions were poor, costing less than the upkeep of slaves, and the slowing of the incoming of new slaves - Brazil was the last country in the Western world to abolish slavery. The Brazilian government was also under pressure from Britain, that sought to put a stop to slave trade in order to expand production in its own colonies. One example is the sugar, produced both in Brazil and in the British colony of the West Indies; the British strove to ensure that the Brazilians would get no advantage in the world markets by using slaves.

The Lei Áurea had additional effects besides the freeing of all slaves; bereft of slaves and lacking hands, the plantation owners (fazendeiros ) had to recruit workers elsewhere and thus organized, in the 1890s, the Sociedade Promotora de Imigração ("Society for the Promotion of Emigration)". Another effect was an uproar among Brazilian slave owners and upper classes, resulting in the toppling of the monarchy and the establishment of a republic in 1889 - indeed, the Lei Áurea is often regarded as the most immediate (but not the only) cause for the fall of monarchy in Brazil.