This list records the incumbents of the Roman Catholic Diocese of Hildesheim (German: Bistum Hildesheim). Between 1235 and 1803 the bishops simultaneously officiating as rulers of princely rank (prince-bishop) in the Prince-Bishopric of Hildesheim (German: Hochstift Hildesheim), a state of imperial immediacy within the Holy Roman Empire. Hildesheim is the seat of the bishops and the cathedral chapter.
Between 1235 and 1803 the elected and papally confirmed bishops of the Hildesheim See were additionally imperially invested princely power as prince-bishops. In 1235 part of the Hildesheim diocesan territory, the episcopal and capitular temporalities (Stift) were disentangled from the Duchy of Brunswick and Lunenburg and became an own territory of imperial immediacy called Prince-Bishopric of Brunswick and Lunenburg (German: Hochstift Hildesheim), a vassal of the Holy Roman Empire. The prince-bishopric was an elective monarchy, with the monarch being the respective bishop usually elected by the Hildesheim Cathedral chapter and confirmed by the Holy See, or exceptionally only appointed by the Holy See. Papally confirmed bishops were then invested by the emperor with the princely regalia, thus the title prince-bishop. However, sometimes the respective incumbent of the see never gained a papal confirmation as bishop (lacking canonical qualification; e.g. Ferdinand of Bavaria and Frederick of Denmark), but was still invested the princely regalia. The respective incumbents of the see bore the following titles: