The building dates back to the IX century and was erected thanks to the Michiel, Minotto and Miani families. It probably took the place of an ancient oratory dedicated to St Cecilia; the new building was instead dedicated to St Cassian, bishop and martyr.
The building underwent various reconstructions and restorations as early as the XII century when it was then rebuilt according to the Venetian-Byzantine cannons. Further works were carried out in the XII century and the belltower was completed in the mid-XIV century. In 1611 work was carried out internally, three aisles were created with flat-ended side chapels that can still be seen today. In the XIX century new restorations led to the removal of the portico on the facade, taking away much of the beauty of the place and leaving the side facing Campo San Cassiano bare.
The cross vault ceiling is pleasantly decorated with frescoes by Costantino Cedini, and among the other masterpieces within the church we can admire the ‘Crucifixion’, the ‘Resurrection of Christ between St Cassian and Cecilia’, the ‘Descent into Limbo’ by Jacopo Tintoretto and the altarpiece of Giovanni Battista Pittoni depicting ‘The Virgin with child, St Charles Borromeo and St Philip Neri’. The wonderful altarpiece of Antonello da Messina, ‘The Virgin with St Michael and other Saints’ — torn from the walls of the San Cassiano church and divided into parts in the early years of the 1600s— is today kept in the Kunsthistorisches Museum of Vienna.
Johannes Sadeler is buried in the church, a skilled copper engraver from Bruxelles, who carved the plate of the Resurrection of Tintoretto.