Infante Duarte of Portugal, 5th Duke of Guimarães (March 1541, in Almeirim – 28 November 1576, in Évora) was a Portuguese infante (prince), son of Duarte of Portugal, 4th Duke of Guimarães and his wife, Isabel of Braganza.
He served as Constable of the Kingdom, the highest military authority in the Portuguese Empire, second only to the monarch.