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.

Wittenberg, is the fourth-largest town in Saxony-Anhalt, Germany. Wittenberg is situated on the River Elbe, 60 kilometers (37 mi) north of Leipzig and 90 kilometers (56 mi) south-west of Berlin, and has a population of 46,008 (2018).