The Grand Mosque of Makkah, also called the Great Mosque of Mecca, is the largest mosque in the World, and surrounds Islam's holiest place, the Kaaba, in the city of Mecca, Hejaz, Saudi Arabia. Muslims face in the Qiblah while performing Salah. One of the Five Pillars of Islam requires every Muslim to perform the Hajj, one of the largest annual gatherings of people in the world, at least once in their lifetime if able to do so, including Tawaf of the Kaaba. It is also the main phase for the Umrah, which is the lesser pilgrimage that can be undertaken any time of the year.

The Grand Mosque includes other important significant sites in Islam including the Black Stone, Well of Zamzam, Station of Abraham, and Safa and Marwa. It is always open, regardless of date or time. It has gone under major renovations by various caliphs, sultans and kings, and it is now under the control of the Custodian of the Two Holy Mosques.