世袭君主制，是君主制政体的最常见形式。世界上大多数现存及曾经存在的君主制国家采用这种政体。与其相对的制度是选举君主制。

在世袭君主制制度中，所有君主来自于同一个家族，王位在家族内部从一个成员传给另一个成员（通常是父传子，也有可能是兄传弟、叔传侄等等）。世袭系统有政权稳定、延续性好和可预测的优点，这来源于家族成员之间的忠诚和亲和力。

举例来说，当一位世袭君主去世或退位后，王位通常会传给下一代的直系血亲，如他或她的孩子，而且往往是较年长者。当这个孩子死了，王位将再传给他的孩子；如果此人绝嗣，则会传给他的兄弟、姐妹、侄子或其他亲属。为了维持这种体系，世袭君主制常常需要以法律形式制定一个明确的继承顺序，以决定一位君主去世之后，谁有最优先的权利成为下一位君主。现代的世袭君主制国家所采用的继承顺序通常基于长子继承权，但也存在着其他的继承体系，如最年长男性亲属继承、在世君主指定继承和交替继承，这些体系在以前的君主制政体中应用得更为普遍。

A hereditary monarchy is one in which the crown is passed down from one member of the royal family to another.

It is historically the most common type of monarchy and remains the dominant form in extant monarchies. It has the advantages of continuity of the concentration of power and wealth and predictability of who controls the means of governance and patronage. Provided that the monarch is competent, not oppressive, and maintains an appropriate royal dignity, it might also offer the stabilizing factors of popular affection for and loyalty to the royal family. The adjudication of what is oppressive, dignified and popular tends to remain in the purvue or the monarch. The main disadvantage is the heir apparent may be physically or temperamentally unfitted to rule. Other disadvantages are the inability of a people to choose their head of state, the ossified distribution of wealth and power across a broad spectrum of society, and the continuation of outmoded religious and social-economic structures mainly for the benefit of the Monarch, their families, and supporters.