Al-Mansur ibn al-Nasir (Arabic: المنصور بن الناصر) (died 1104) was the sixth ruler of the Hammadids in Algeria (1088–1104).

Al-Mansur ibn al-Nasir succeeded his father Nasir ibn Alnas in 1088.^[1] In 1090, he left the Kal'a (Beni Hammad Fort), the traditional capital of the Hammadids, to settle in Béjaïa (Bougie) with his troops and his court,^[2] which he considered less accessible to the Nomads.^[1] He left the region because of the destruction caused by the arrival of the Banu Hilal.^[2] His father had already prepared this transfer by transforming a fishing port into a city he calls An-Nasiriya but which was to assume the name of Bougie,^[1] the name of a tribe that inhabited this region.^[2] Al-Mansur built public buildings, palaces, a water distribution network and gardens in Bejaia.^[3] The Hammadid kingdom thus abandoned its nomadic origins and became sedentary.^[3] The Kal'a was not completely abandoned by al-Mansur and he even embellished it with a number of palaces.^[1] The Hammadids therefore had two capitals joined by a royal road at this time.^[4]