Bishopric of Merseburg was a former episcopal see in Saxony with the center in Merseburg, founded at the same time in the same manner as those of Meissen and Zeitz, as part of the plan for binding more closely to the Holy Roman Empire the territory of the Wends on the right bank of the Saale (967). The Merseburg Cathedral was the main church within the diocese.

The first bishop was Boso, a monk of Ratisbon, distinguished by his missionary labors amongs the Wends. His successor Gisiler procured the suppression of the see through Otto II's power over Pope Benedict VII in 981; but this step was so clearly against the interests of the Church that it was revoked in 998 or early in 999 at a Roman synod. The diocese did not, however, recover all its former territory, and was now almost exclusively a missionary jurisdiction among the Wends, who were not fully converted to Christianity until the middle of the 12th century.

The Protestant Reformation was forcibly established here during the episcopate of Sigismund von Lindenau after his protector Duke Henry I of Brunswick-Wolfenbüttel had been driven out of by the Schmalkaldic League in 1542. The electors of Saxony thereafter put in members of their own house with the title of administrator, and from 1652 to 1738 with that of Duke of Saxe-Merseburg.

By the decision of the Congress of Vienna, three-fourths of the diocesan territory was assigned to the Kingdom of Prussia, the rest remaining Saxon; the religious attitude of the people was by that time almost entirely Lutheran.