Chapel of St. Casimir

Interior of the Chapel of Saint Casimir
General information
Architectural style	Baroque architecture
Town or city	Vilnius
Country	Lithuania
Construction started	1623
Completed	1636
Designations	(see Designated landmark)

The Chapel of Saint Casimir is a chapel dedicated to Saint Casimir in Vilnius Cathedral. The chapel was built in 1623–36 after Prince Casimir (1458–1484) was canonized as saint. It was built and decorated in the Baroque style by Italian sculptors and architects commissioned by Sigismund III Vasa, King of Poland and Grand Duke of Lithuania. The centerpiece of the chapel is a faux marble altar which holds the silver sarcophagus with Casimir's remains and the painting Three-Handed St. Casimir.

The chapel has two expressive murals by Florentine artist Michelangelo Palloni completed during the restoration work in 1692.The Opening of the Coffin of St. Casimir measures 285 by 402 centimetres (112 in × 158 in) and decorates the east wall. It depicts the opening of St. Casimir's coffin on August 16, 1604 during his canonization proceedings. The body in the coffin was found intact, 120 years after the burial. The saint is wearing a long red robe, decorated with stoat fur, and a ducal crown. Bishop Benedykt Woyna (), who wrote to Rome of a wonderful smell after the lid was lifted, has his hands raised to heaven in praise of the Lord. Kneeling at the head of the saint is Gregorius Swiecicki, the canon at Vilnius Cathedral chapter, who was entrusted with Casimir’s canonization process. Jan Kazimierz Sapieha who commissioned the painting stands on the right; Virgin Mary and Saint Peter, dressed in clothes of the time, stand on the left. Around them are priests with long candles in their hands.Resurrection of Ursula measures 295 by 402 centimetres (116 in × 158 in) and decorates the west wall. It depicts the first known miracle of St. Casimir. After the death of a young girl Ursula, her father went to the coffin of the prince to pray for her and the girl miraculously resurrected. The artist skillfully depicts surprise and astonishment of the father, other relatives, and clergy.