The Ajyad Fortress (Turkish: Ecyad Kalesi) was an Ottoman fort built in Mecca, in what is now Saudi Arabia, in the late 18th century. It was destroyed by the Saudi government in 2002 for commercial development, sparking global outcry.

In 1781 (or 1777 or 1780, according to some sources), the fortress was built in order to protect the Kaaba and Islamic shrines in Mecca from invaders. The fort covered some 23,000 m² (250,000 sq ft) on Bulbul Mountain (a spur of Jebel Kuda) overlooking the Masjid al-Haram from the south.

Ajyad Fortress was demolished and most of Bulbul Mountain levelled by the Saudi government in 2002 to make space for the $533 million construction projectAbraj Al Bait Towers. The 11 high-rise towers will consist of apartments, a twin-tower five-star hotel, restaurants, and a shopping centre, all to be built by the Saudi Binladin Group.

The destruction of the historic structure stirred both domestic and international protest. The Turkish Foreign Minister İsmail Cem İpekçi and other institutions tried to prevent the demolition. The Turkish Democratic Left Party (DSP) Deputy Ertuğrul Kumcuoğlu even suggested a boycott on travelling to Saudi Arabia. The Turkish Ministry of Culture and Tourism condemned the obliteration of the fortress, comparing the act to the destruction of the Buddhas of Bamyan, and accusing the Saudi authorities of "continuing with their policy of demolishing Ottoman heritages."

Ajyad is a neighborhood of Mecca in Makkah Province, in western Saudi Arabia. It contains the Ajyad Fortress.