St. Stephen's Church, Gothic parish church in Mainz-Altstadt, Germany

St. Stephen's Church is a three-aisled Gothic hall church with choirs at both the east and west ends. A large octagonal bell tower rises above the western choir. The exterior is built of pale stone and reddish-brown masonry, with a tall square tower topped by a steep dark pyramidal roof and pointed-arched windows with tracery.

Archbishop Willigis founded St. Stephan in 990 on Mainz's highest hill, likely at the wish of Empress Dowager Theophanu, as a prayer site for the Empire. Archbishop Bardo replaced the first wooden church with a stone one from 1043. The present Gothic hall church was begun around 1267 and finished around 1340, keeping the double-choir plan. A powder-tower explosion in 1857 and the air raid of 27 February 1945 destroyed much of the furnishings and vaults.

The nine choir windows were made by Marc Chagall from 1978 until his death in 1985, at the invitation of parish priest Klaus Mayer, and were meant as a contribution to Jewish-German reconciliation. Chagall designed the glass and did the black-lot painting himself; his pupil Charles Marq continued the remaining windows. The name Stephan goes back to the Greek word for wreath or crown.

The nave and choir lost their vaults in the Second World War and are now covered by a flat wooden ceiling. The Chagall windows are in the front part of the church, near the choir; the cloister on the south side was rebuilt between 1968 and 1971. The church stands on the highest hill of the old town, with Willigisplatz to its east.

The five bells that hung in the tower melted in the fire after the air raid of 27 February 1945. For decades the parish used the Beatrix bell, cast in 1493 and taken from the ruined church of St. Emmeran; it is the third-oldest bell in Mainz. In 2008 a donation from the technology company Schott funded three new bells, and on 27 February 2009 all of them rang together for the first time.