Knight Jacob Curiel (26 September 1587 - 3 April 1664), known by his alias Duarte Nunes da Costa, was a Sephardi Jewish merchant, diplomat, and nobleman.Curiel was educated at the University of Coimbra and the University of Bologna.
He served as Agent to the Spanish, then Portuguese, Crown in Hamburg, Germany.On 14 June 1641 Jacob Curiel was ennobled by Joao IV of Portugal.