The Passio secundum Joannem or St John Passion (German: Johannes-Passion), BWV 245, is a Passion or oratorio by Johann Sebastian Bach, the older of two surviving Passions by Bach. It was written during Bach's first year as director of church music in Leipzig and was first performed on April 7, 1724, at Good Friday Vespers at the St. Nicholas Church.
The structure of the work falls in two halves, intended to flank a sermon. The anonymous libretto draws on existing works (notably Brockes') and is compiled from recitatives and choruses narrating the Passion of Christ as told in the Gospel of John, ariosos and arias reflecting on the action, and chorales using hymn tunes and texts familiar to a congregation of Bach's contemporaries. Compared with the St Matthew Passion, the St John Passion has been described as more extravagant, with an expressive immediacy, at times more unbridled and less "finished".
The work is most often heard today in the 1724 version although Bach revised it in 1725, 1732, and 1749, adding several numbers. "O Mensch, bewein dein Sünde groß", a 1725 replacement for the opening chorus, found a new home in the 1736 St Matthew Passion but several arias from the revisions are found only in the appendices to modern editions.