Mahdia is a city in Tunisia.
Mahdia may also refer to:
- Mahdia Governorate in Tunisia
- Mahdia, Guyana
- History of Mahdist Sudan
- Mehdya, a city in Morocco
Mahdiyya or al-Mahdiyya may refer to:
- The Fatimid caliphate of Abdullah al-Mahdi Billah (909–934)
- Mahdist Sudan (1885–1899)