All Saints' Church, commonly referred to as Schlosskirche to distinguish it from the Stadtkirche of St. Mary's, sometimes known as the Reformation Memorial Church, is a Lutheran church in Wittenberg, Saxony-Anhalt, Germany. It is the site where, according to Philip Melanchthon, the Ninety-five Theses were posted by Martin Luther in 1517, launching the beginning of the Protestant Reformation.

The Stadt- und Pfarrkirche St. Marien zu Wittenberg is the civic church of the German town of Lutherstadt Wittenberg. The reformers Martin Luther and Johannes Bugenhagen preached there and the building also saw the first celebration of the mass in German rather than Latin and the first ever distribution of the bread and wine to the congregation – it is thus considered the mother-church of the Protestant Reformation. In 1996, it was inscribed on the UNESCO World Heritage List along with Castle Church of All Saints (Schlosskirche), the Lutherhaus, the Melanchthonhaus, and Martin Luther's birth house and death house in Eisleben, because of its religious significance and testimony to the lasting, global influence of Protestantism.