The history of the Electoral Palace began already in the 16th century. At that time, St. Martin's Castle stood on the site. It served Archbishop Diether von Isenberg as his archiepiscopal residence. The palace building was intended to be a representative extension of St. Martin's castle. But in 1552, the latter was ravaged by fire caused by armed conflicts. It was rebuilt by Elector Daniel Brendel von Homburg between 1555 and 1582.
In 1627, work began on the construction of the eastern wing along the Rhine under Elector Friedrich von Greiffenclau as an archiepiscopal residence in Renaissance style. After Greiffenklau's death, the work was continued by Anselm Casimir von Wamboldt. The architect was Matthias von Saarburg, a Capuchin monk.
In 1678, the east wing was completed under Elector Damian Hartard von der Leyen.
In 1687, work began on the construction of the north-east wing (today containing event rooms) under Archbishop Anselm von Ingelheim. The wing was completed in 1752 under Elector von Ostein.
In 1792, the last Elector of Mainz, Friedrich Carl von Erthal, was evicted. A period of almost 50 years of neglect then followed for the Electoral Palace. As a result of plundering, nothing was left of the sumptuous and magnificent interior furnishings. It was partially demolished, sold off, auctioned and destroyed. After the dissolution of the Electorate, the palace served at various times as a barracks, military hospital and depot.
In 1804, a decree by Napoleon designated the Electoral Palace as a temporary transit camp. Later, the notorious robber chief Schinderhannes, with his henchmen, was condemned to death here.
In 1827, the Electoral Palace passed into the possession of the City of Mainz and was restored with funds from the Grand Duchy of Hesse-Darmstadt and the City of Mainz.
In 1945, the entire interior furnishings with the valuable ceiling paintings and stucco ceilings were totally destroyed during a bombing raid. Only the outer walls were left standing.
In 1949, the Electoral Palace was rebuilt by the City of Mainz as a venue for events. It was possible to save the outer walls, but inside, it lost some of its magnificent structural substance.
On 31 December 1949, the first event took place in the Electoral Palace: a New Year's Ball of the Mainzer Carneval Verein e.V.
Since then, the Electoral Palace has served as a venue for celebrations, meetings and marriages. Also the location is known for the television session "Mainz remains Mainz, as it sings and laughs", which has been broadcast for years.