The oldest mosques in the world can refer to the oldest, surviving mosque building or to the oldest mosque congregation. There is also a distinction between old mosque buildings in continuous use as mosques and others no longer used as mosques. In terms of congregations, there are early established congregations that have been in continuous existence, and early congregations that ceased to exist.

The major regions, such as Africa and Eurasia, are sorted alphabetically, and the minor regions, such as Arabia and South Asia, are sorted by the dates in which their first mosques were reportedly established, more or less, barring those that are mentioned by name in the Quran.

To be listed here a site must:

The following are treated as the oldest mosques or sanctuaries mentioned in the Quran: