Jan Firlej (c. 1521, Dąbrowica, Lublin County – 1574, Kock) was a Polish nobleman (szlachcic), and Calvinist activist. Jan became Crown Grand Marshal in 1563 and starost of Kraków in 1572. He agreed with the candidature of Henryk Walezy for the Polish throne only on the condition that Henryk signing the Henrican articles. Voivode of Bełz, Lublin and Kraków. Around 1555 he founded a Calvinist church in Kock, and build a family residence there.