John Cantius was a 15th-century Polish priest, theologian, and philosopher who taught at the Kraków Academy. Born in Kęty in 1390, he earned a doctorate in philosophy before pursuing holy orders. He later served as the director of the theology department at his alma mater, where he also spent significant time transcribing religious manuscripts. Known for his profound humility and his dedication to the impoverished, he lived a life of simplicity, frequently providing alms to needy students and the poor.