The term sacred mysteries generally denotes the area of supernatural phenomena associated with a divinity or a religious ideology. The term has two senses, which often overlap:

1. Religious beliefs, rituals or practices which are kept secret from non-believers, or lower levels of believers, who have not had an initiation into the higher levels of belief (the concealed knowledge may be called esoteric).
2. Beliefs of the religion which are public knowledge but cannot be explained by normal rational or scientific means.

Although the term "mystery" is not often used in anthropology, access by initiation or rite of passage to otherwise secret beliefs is an extremely common feature of indigenous religions all over the world.