Manuel Cardoso was a Portuguese composer and organist. With Duarte Lobo and John IV of Portugal, he represented the "golden age" of Portuguese polyphony.
Cardoso is not known to be related to an older contemporary composer of the same name; the precentor Manuel Cardoso, who published a book of Latin passions in Leiria in 1575.
Cardoso's works are models of Palestrinian polyphony, and are written in a refined, precise style which completely ignores the development of the Baroque idiom elsewhere in Europe. His style has much in common with Tomás Luis de Victoria, in its careful treatment of dissonance, occasional polychoral writing, and frequent cross-relations, which were curiously common among both Iberian and English composers of the time. Three books of masses survive; many of the works are based on motets written by King John IV himself, and others are based on motets by Palestrina. Cardoso was widely published, often with the help of King John IV to defray costs. Many of his works—especially the elaborate polychoral compositions, which probably were the most progressive—were destroyed in the Lisbon earthquake and fire of 1755.