The Church of St. Rupert (German: Ruprechtskirche) is a church in Vienna, Austria. Traditionally considered to be the oldest church in the city, it is dedicated to Saint Rupert of Salzburg, patron saint of the salt merchants of Vienna. It is located in one of the oldest parts of the city, the section of the Roman Vindobona.

There is currently some debate whether the Ruprechtskirche is truly the oldest church in Vienna. Discoveries of old foundations under the Peterskirche and old graves under the Stephansdom have disputed the certainty of this label.