Kostel svatého Šimona a Judy, Gothic church in Old Town, Prague, Czech Republic

The Church of Saints Simon and Jude is a Gothic structure in Prague's Old Town with pointed arches and a large organ inside. The interior features stone vaults and tall Gothic windows that create height and allow light to fill the space.

A hospital founded on the site in 1354 was adjoined by a chapel consecrated by Bishop Arnošt of Pardubice. In 1615–1620 the Bohemian Brethren built the present church, consecrated on 14 July 1620; after the Battle of White Mountain Emperor Ferdinand II gave it to the Brothers Hospitallers of Saint John of God. High Baroque remodelling followed about a century later, with facades reworked in 1720–1721.

The church functions today as a concert venue where classical music is performed regularly throughout the year. The stone interior with its vaults creates natural acoustics that musicians and audiences find appealing.

The church stands on U Milosrdných Street in the Old Town, beside the Hotel InterContinental, not far from the Vltava embankment. It is a concert hall rather than a parish church, so visits depend on performances; the Prague Symphony Orchestra FOK, which uses it, publishes the programme. The building has floor heating installed during the 1990s restoration.

In 1847 the surgeon Celestine Opitz performed what Alois Jirásek's novel F. L. Věk describes as the world's first operation under anaesthesia at the adjoining St. Francis Hospital; the claim later helped the hospital and church win support from Masaryk, Beneš and Pope Pius XI.