Mikołaj Zieleński (Zelenscius, birth and death dates unknown) was a Polish composer.
Zieleński's only known surviving works are two 1611 liturgical cycles of polychoral works, the Offertoria/Communes totius anni. These were dedicated to the Archbishop of Gniezno, Wojciech Baranowski. The sets consist of large-scale double- and triple-choir antiphons, as well as some monodic works typical of the Seconda pratica style of early Monteverdi. Zieleński's music is the first known Polish music set in the style of the Baroque.
