君权神授说，或作天授君权说（英语：Divine right of kings），是古代以宗教来主导政治时期君主为了巩固自己的权力而提倡的一种法。即指自己是天命派遣，于凡间管治世人，是神在人间的代表，作为人民只可遵从君主的指示去做，不能反抗。这个说法在世界各地都曾出现过，但在启蒙时代后，人们思想开始由宗教指导中释放出来，使这个说法的相信者变得越来越少，在现代社会这个说法早已为不可信及无稽。

The divine right of kings, divine right, or God's mandate is a political and religious doctrine of royal and political legitimacy. It asserts that a monarch is subject to no earthly authority, deriving the right to rule directly from the will of God. The king is thus not subject to the will of his people, the aristocracy, or any other estate of the realm, including (in the view of some, especially in Protestant countries or during the reign of Henry VIII of England) the Catholic Church. It is often expressed in the phrase "by the Grace of God," attached to the titles of a reigning monarch.