Minas Geraes, spelled Minas Gerais in some sources, was a dreadnought battleship of the Brazilian Navy. Named in honor of the state of Minas Gerais, the ship was laid down in April 1907 as the lead ship of its class, making the country the third to have a dreadnought under construction and igniting a naval arms race between Brazil, Argentina, and Chile.
Two months after its completion in January 1910, Minas Geraes was featured in Scientific American, which described it as "the last word in heavy battleship design and the ... most powerfully armed warship afloat". In November 1910, Minas Geraes was the focal point of the Revolt of the Lash. The mutiny, triggered by racism and physical abuse, spread from Minas Geraes to other ships in the Navy, including its sister , the elderly coastal defense ship Deodoro, and the recently commissioned cruiser . Led by João Cândido Felisberto, the mutineers threatened to bombard the Brazilian capital of Rio de Janeiro if their demands were not met. As it was not possible to end the situation militarily—the only loyal troops nearby being small torpedo boats and army troops confined to land—the National Congress of Brazil conceded to the rebels' demands, including a grant of amnesty, peacefully ending the mutiny.
When Brazil entered the First World War in 1917, Britain's Royal Navy declined Brazil's offer of Minas Geraes for duty with the Grand Fleet because the ship was outdated; it had not been refitted since entering service, so range-finders and a fire-control system had not been added. São Paulo underwent modernization in the United States in 1920; in 1921, Minas Geraes received the same treatment. A year later, Minas Geraes sailed to counter the first of the Tenente revolts. São Paulo shelled the rebels' fort, and they surrendered shortly thereafter; Minas Geraes did not fire its guns. In 1924, mutineers seized São Paulo and attempted to persuade the crews of Minas Geraes and several other ships to join them, but were unsuccessful.