The Fatimid dynasty was an Arab dynasty that ruled the Fatimid Caliphate, between 909 and 1171 CE. Descended from Fatima and Ali, and adhering to Isma'ili Shi'ism, they held the Isma'ili imamate, and were regarded as the rightful leaders of the Muslim community. The line of Nizari Isma'ili imams, represented today by the Aga Khans, claims descent from a branch of the Fatimids. The Alavi Bohras, predominantly based in Vadodara, also claim descent from the Fatimids.

A dynasty is a sequence of rulers from the same family, usually in the context of a monarchical system, but sometimes also appearing in republics. A dynasty may also be referred to as a "house", "family" or "clan", among others.