Alegrete is a municipality in Rio Grande do Sul located in southern Brazil. Its medium altitude is 102 m. Its estimated population in 2020 was 73,028 inhabitants and the total area is 7,803.967 km2 (the largest municipality of the State and of Southern Brazil). Its inhabitants are called Alegretenses. Alegrete was settled in 1816 and became a municipality in 1857. It is the hometown of the abolitionist leader Franklin Gomes Souto, of the politician, diplomat and statesman Osvaldo Aranha, first President of the United Nations General Assembly, and of the Brazilian poet Mário Quintana. Every 20 September (Ragamuffin War Day), about 8,000 young, adult and old horsemen and horsewomen parade through its streets, using their native costumes and riding their horses with trappings. Alegrete is served by Gaudêncio Machado Ramos Airport. The municipality contains part of the 351 ha Ibirapuitã Biological Reserve, a fully protected conservation unit created in 1982 to preserve an area of the pampas biome.