Manuel Deodoro da Fonseca (; 5 August 1827 – 23 August 1892) was a Brazilian politician and military officer who served as the first President of Brazil. He took office after heading a military coup that deposed Emperor Pedro II and proclaimed the Republic in 1889, disestablishing the Empire, and stepped down little more than two years after his election in 1891, under great political pressure. He is therefore the first Brazilian President to have resigned from office.