Ad-Din is a
laqab, a component of some Arabic names, meaning "of the faith." People with this laqab include:
- Jamal ad-Din (astronomer)(13th century), Persian Moslem astronomer
- Salah ad-Din, better known as Saladin (1138-1193), ruler of Syria and Egypt
- Al-Afdal ibn Salah ad-Din (born 1160), son of Saladin and second emir of Damascus
- Nur ad-Din (1118-1174), Zengid dynasty ruler of Syria
- Ismat ad-Din Khatun (died 1186), wife of Nur ad-Din
- Ali ibn Sabr ad-Din (lived after 1344), Governor of Ifat
- Haqq ad-Din II (ruled late 14th century), Sultan of Ifat
- Sa'ad ad-Din II (ruled c. 1400), Sultan of Ifat
- Sabr ad-Din II (died 1422/1423), King of Adal
- Mansur ad-Din (died 1424), Sultan of Adal
- Badlay ibn Sa'ad ad-Din (died 1445), Sultan of Adal
- Muhammad ibn Azhar ad-Din (reigned 1488-1518), Sultan of Adal
- Nasr ad-Din (Lamtuna) (in power 1644-1674), Berber leader
- Jamal ad-Din (disambiguation) - several persons of this name
- Nasir al-Din (disambiguation) includes Nasir ad-Din - several persons of this nameSee also
- Izz al-Din, or Izz ad-Din, honorific title incorporated in certain Arabic names
- Salah ad Din Governorate, Iraq