Stephen (I) from the kindred Csák (Hungarian: Csák nembeli (I.) István; c. 1235 – 1279/83) was a Hungarian noble and landowner, who held secular positions during the reign of king Ladislaus IV. His nephew and heir was the oligarch Matthew III Csák, who, based on his uncles' acquisitions, became the de facto ruler of his domain independently of the king and usurped royal prerogatives on his territories.