The Great Mosque of Mecca, commonly known as al-Masjid al-Ḥarām (Arabic: اَلْمَسْجِدُ ٱلْحَرَامُ‎, romanized: al-Masjid al-Ḥarām, lit. 'The Sacred Mosque'), is a mosque that surrounds the Kaaba in the city of Mecca, in the Hejazi region of Saudi Arabia. It is a site of pilgrimage for the Hajj, which every Muslim must do at least once in their lives if able, and is also the main phase for the ʿUmrah, the lesser pilgrimage that can be undertaken any time of the year. The rites of both pilgrimages include circumambulating the Kaaba within the mosque. The Great Mosque includes other important significant sites, including the Black Stone, the Zamzam Well, Maqam Ibrahim, and the hills of Safa and Marwa.

The Great Mosque is the largest mosque in the world, and the second largest building in the world behind the Boeing Everett Factory. The Great Mosque has undergone major renovations and expansions through the years.^[7] It has passed through the control of various caliphs, sultans and kings, and is now under the control of the King of Saudi Arabia who is titled the Custodian of the Two Holy Mosques.