António de Saldanha da Gama, Count of Porto Santo

António de Saldanha da Gama, Count of Porto Santo (1778–1839) was a Portuguese plenipotentiary at the Congress of Vienna in 1815. While at the Congress he signed a number of treaties and documents on behalf of Prince Regent John of Portugal including the Declaration of the Powers, on the Abolition of the Slave Trade, on 8 February 1815.