Cardinal Franciszek Macharski was 89 and died at hospital.
He had been visted by Pope Francis five days ago, as the pontiff was in Poland for World Youth Day.
Francis prayed with the clergyman at his bedside in a Krakow hospital.
Cardinal Macharski served for many years as Archbishop of Krakow, inheriting a position opened by the election of Pope John Paul II.
He became Krakow archbishop in 1978, replacing Karol Wojtyla, who became the first Polish pope that year. He served in that position until 2005, which was also the year that John Paul died after a 27-year pontificate.
