采邑主教，或称亲王主教，是指以教会诸侯的身分治理着一个或是多个公国，同时拥有政教二重权力的主教。这些世俗地位并不是源自于担任主教者在领受圣职前获得的贵族身分，而是附加于这些主教职位上，随着主教职务的传承而跟着继承。当该主教为总教区主教时，则被称作采邑总主教或采邑大主教，此外相似的神职身分还有采邑修道院长。一般而言，这些主教治理的公国会和他管理的教区部分或完全重叠，但并非全都如此，如科隆因为从科隆选侯国独立成为自由城市，因此科隆总主教的领地就不包含科隆一地。

在西欧自4世纪起，罗马帝国因为蛮族的入侵以及自身内乱等原因而衰亡，一些城邦的主教必须挑起或插手罗马指挥官的职责，管理世俗政务，有时还必须带领军队抵御外敌。而在封建社会形成后，主教等高级教士又从高端的领主那获得封地，进而同时拥有教会上的头衔与世俗领主的地位。

A prince-bishop is a bishop who is also the civil ruler of some secular principality. Thus the principality ruled politically by a prince-bishop could wholly or largely overlap with his diocesan jurisdiction, since some parts of his diocese, even the city of his residence, could be exempt from his civil rule, obtaining the status of free imperial city. If the episcopal see is an archbishopric, the correct term is prince-archbishop; the equivalent in the regular (monastic) clergy is prince-abbot. A prince-bishop is usually considered an elected monarch.