The St Matthew Passion (German: Matthäuspassion), BWV 244, is a Passion, a sacred oratorio written by Johann Sebastian Bach in 1727 for solo voices, double choir and double orchestra, with libretto by Picander. It sets the 26th and 27th chapters of the Gospel of Matthew (in the Luther Bible) to music, with interspersed chorales and arias. It is widely regarded as one of the masterpieces of Baroque sacred music. The original Latin title Passio Domini nostri J.C. secundum Evangelistam Matthæum translates to "The Passion of our Lord Jesus Christ according to the Evangelist Matthew".

The St Matthew Passion is the second of two Passion settings by Bach that have survived in their entirety, the first being the St John Passion, first performed in 1724.

Little is known with certainty about the creation process of the St Matthew Passion. The available information derives from extant early manuscripts, contemporary publications of the libretto, and circumstantial data, for instance in documents archived by the Town Council of Leipzig.

The St Matthew Passion was probably first performed on 11 April (Good Friday) 1727 in the St. Thomas Church, and again on 15 April 1729, 30 March 1736, and 23 March 1742. Bach then revised it again between 1743 and 1746.

In Leipzig it was not allowed to paraphrase the words of the Gospel in a Passion presentation on Good Friday. A setting of the then-popular Brockes Passion libretto, largely consisting of such paraphrasing, could not be done without replacing the paraphrases by actual Gospel text. That was the option chosen by Bach for his 1724 St John Passion. In 1725 Christian Friedrich Henrici, a Leipzig poet who used Picander as his pen name, had published Erbauliche Gedanken auf den Grünen Donnerstag und Charfreytag ("Edifying Thoughts on Maundy Thursday and Good Friday"), containing free verse suitable for a Passion presentation in addition to the Gospel text. Bach seems to have stimulated the poet to write more of such verse in order to come to a full-fledged libretto for a Passion presentation combined with the Passion text chapters 26 and 27 in the Gospel of St Matthew.

Since 1975, it has usually been assumed that Bach's St Matthew Passion was first performed on Good Friday 11 April 1727, although its first performance may have been as late as Good Friday 1729, as older sources assert. The performance took place in the St. Thomas Church (Thomaskirche) in Leipzig. Bach had been Thomaskantor (i.e., Cantor, and responsible for the music in the church) since 1723. In this version the Passion was written for two choruses and orchestras. Choir I consists of a soprano in ripieno voice, a soprano solo, an alto solo, a tenor solo, SATB chorus, two traversos, two oboes, two oboes d'amore, two oboes da caccia, lute, strings (two violin sections, violas and cellos), and continuo (at least organ). Choir II consists of SATB voices, violin I, violin II, viola, viola da gamba, cello, two traversos, two oboes (d'amore) and possibly continuo.

Klagt, Kinder, klagt es aller Welt, BWV 244a, a cantata of which only the text is extant, was performed 24 March 1729 in Köthen at a memorial service held some months after the death of Leopold, Prince of Anhalt-Köthen. The music of the cantata consisted largely of music adapted from the St Matthew Passion.

At the time only men sang in church: high pitch vocal parts were usually performed by treble choristers. In 1730, Bach informed the Leipzig Town Council as to what he saw as the number of singers that should be available for the churches under his responsibility, including those for the St. Thomas Church: a choir of twelve singers, plus eight singers that would serve both St. Thomas and the Peterskirche. The request was only partially granted by the Town Council, so possibly at least some of the Passion presentations in St. Thomas were with fewer than twenty singers, even for the large scale works, like the St Matthew Passion, that were written for double choir.