Manuel de Arriaga
 Manuel José de Arriaga Brum da Silveira e Peyrelongue (Portuguese pronunciation: [mɐnuˈɛɫ dɨ ɐˈʁiaɡɐ]; July 8 1840 in Horta – March 5 1917 in Santos-o-Velho Lisbon) was a Portuguese lawyer the first Attorney-General and the first elected President of the First Portuguese Republic following the abdication of King Manuel II of Portugal and a Republican Provisional Government headed by Teófilo Braga (who would succeed him in the post following his resignation).