Santa Maria delle Grazie ("Holy Mary of Grace") is a church and Dominican convent in , included in the UNESCO World Heritage sites list. The church contains the mural of the Last Supper by , which is in the refectory of the convent.

The Duke of Milan Francesco I Sforza ordered the building of a Dominican convent and a church in the place where a small chapel dedicated to St. Mary of the Graces was.

The main architect was , the convent was completed by 1469 while the church took more time. The new duke decided to have the church as the Sforza family burial place and rebuild the cloister and the apse which were completed after 1490.

Ludovico's wife Beatrice was buried in the church in 1497.

The apse of the church is widely believed to be by Donato Bramante. However, there's no real evidence of the fact, but that Bramante lived in Milan at the time, and he is once quoted in the acts of the church (a marble delivery in 1494). He continued the gothic style from the first part, but mixed with Romanesque influence.

In 1543, the Holy Crown chapel received a painting by Titian, The Crowning with Thorns. This was carried away by French troops in 1797, after their conquest of Milan.

During World War II, the night of 15 August 1943, bombs dropped by British and American planes hit the church and the convent. Much of the refectory was destroyed, but some walls survived, including the one that holds the Last Supper, which had been sand-bagged for protection.

The Last Supper (Italian: Il Cenacolo or L'Ultima Cena) is a 15th century mural painting in Milan created by Leonardo da Vinci for his patron Duke Ludovico Sforza and his duchess Beatrice d'Este. It represents the scene of The Last Supper from the final days of Jesus, when Jesus announces that one of his Twelve Apostles would betray him.

The Last Supper measures 450 × 870 centimeters (15 feet × 29 ft) and covers an end wall of the dining hall at the monastery of Santa Maria delle Grazie. The theme was a traditional one for refectories, although the room was not a refectory at the time that Leonardo painted it. The main church building had only recently been completed (in 1498), but was remodeled by Bramante, hired by Ludovico Sforza to build a Sforza family mausoleum. The painting was commissioned by Sforza to be the centerpiece of the mausoleum. The lunettes above the main painting, formed by the triple arched ceiling of the refectory, are painted with Sforza coats-of-arms. The opposite wall of the refectory is covered by the Crucifixion fresco by Giovanni Donato da Montorfano, to which Leonardo added figures of the Sforza family in tempera. Leonardo began work on The Last Supper in 1495 and completed it in 1498— but he did not work on the painting continuously. This beginning date is not certain, as "the archives of the convent have been destroyed and our meagre documents date from 1497 when the painting was nearly finished."

The Last Supper specifically portrays the reaction given by each apostle when Jesus said one of them would betray him. All twelve apostles have different reactions to the news, with various degrees of anger and shock. The apostles are identified from a manuscript with their names found in the 19th century. (Before this, only Judas, Peter, John and Jesus were positively identified.)

As early as 1517 the painting was starting to flake. By 1556— fewer than sixty years after it was finished — Leonardo's biographer Giorgio Vasari described the painting as already "ruined" and figures were almost unrecognizable. In 1652 a doorway was cut through the painting, and later bricked up; this can still be seen as the irregular structure near the center base of the painting, so we cannot see Jesus' feet anymore. In 1768 a curtain was hung over the painting for the purpose of protection; it instead trapped moisture on the surface, and whenever the curtain was pulled back, it scratched the paint.

The painting's appearance in the late 1970s was badly deteriorated. From 1978 to 1999 Pinin Brambilla Barcilon guided a major restoration project which undertook to stabilize the painting, and reverse the damage caused by dirt, pollution, and the misguided 18th and 19th century restoration attempts. The refectory was converted to a sealed, climate controlled environment, which meant bricking up the windows.

A common rumor surrounding the painting is that the same model was used for both Jesus and Judas. The story often goes that the innocent-looking young man, a baker, posed at nineteen for Jesus. Some years later Leonardo discovered a hard-bitten criminal as the model for Judas, not realizing he was the same man.

Some writers identify the person to Jesus' right not with the Apostle John but with Mary Magdalene.