Al-Ma'mun () means 'trustworthy', 'trusted', and 'reliable'. People with the name include:
Al-Ma'mun, seventh Abbasid caliph, ruling from 813 to his death in 833 Ma'mun I ibn Muhammad (died 997), Khwarazmshah Ma'mun II (died 1017), Khwarazmshah al-Ma'mun al-Bata'ihi (died 1128), vizier to the Fatimid caliph al-Amir al-Mamun of Toledo (died 1075), Taifa king and a member of the Banu Dil-Nun dynasty Idris al-Ma'mun (died 1232), was a rival Almohad ruler who reigned from 1229 to 1232 See also Abdullah al Mamun (disambiguation)