It is situated on Wawel Hill, between the Vasa Gate and the former seat of the Castle Seminary, in the Cathedral House, which is composed of two 14th-century buildings.
In 1906, Cardinal Jan Puzyna established the diocesan museum in the buildings.
In 1975, cardinal Karol Wojtyla, future Pope John Paul II, decided to transform it into a cathedral museum, where objects from the Wawel Cathedral would be kept and exposed.
On 28 September 1978, on the 20th anniversary of the day he was anointed as bishop, Cardinal Karol Wojtyła ceremonially opened and blessed the Wawel Cathedral Museum, which was to be his last official duty at Wawel before he became pope.
The cathedral museum exhibition presents the most precious objects which were kept in the cathedral treasury: the oldest Polish regalia, handicraft, clothes, paintings and sculptures, as well as the memorabilia related to Pope John Paul II.