As of 2019, which Cathedral has acquired the largest organ outside of the United States?

St. Stephen's Cathedral is a baroque church from 1688 in Passau, Germany, dedicated to Saint Stephen. It is the seat of the Catholic Bishop of Passau and the main church of his diocese.

The current church, a baroque building around 100 metres (328 ft) long, was built from 1668 to 1693 after a fire in 1662 destroyed its predecessor, of which only the late gothic eastern side remains. The cathedral's overall plan was made by Carlo Lurago, its interior decoration by Giovanni Battista Carlone, and its frescos by Carpoforo Tencalla.

Over time, Passau Cathedral has acquired the largest organ outside of the United States. It is also the largest cathedral organ in the world. The organ currently has 17,774 pipes and 233 registers, all of which can be played with the five-manual general console in the gallery. Portions of the organ have their own mechanical-action or electric-action consoles, for a total of six consoles.