The Bishopric of Münster is an ecclesiastical principality in the Holy Roman Empire, located in the northern part of today's North Rhine-Westphalia and western Lower Saxony.

From the sixteenth to the eighteenth centuries, it is often held in personal union with one or more of the nearby ecclesiastical principalities of Cologne, Paderborn, Osnabrück, Hildesheim, and Liège.Münster is bordered by the United Provinces to the west, by Cleves, Vest Recklinghausen, and Mark in the south, Paderborn and Osnabrück in the east.

In the north and northeast it borders East Frisia, Oldenburg and the Electorate of Hanover (est.

1692).As with all the other prince-bishoprics of the Holy Roman Empire, it is important to distinguish between the Prince-Bishopric of Münster and the Diocese of Münster although both entities are ruled by the same individual.

The dioceses are generally larger than the corresponding prince-bishoprics and in the parts that extend beyond the prince-bishopric, the prince-bishop's authority is strictly that of an ordinary bishop and limited to spiritual matters.