The Zirid dynasty (Arabic: الزيريون, romanized: az-zīriyyūn), also known as the Banu Ziri (Arabic: بنو زيري, romanized: banū zīrī), was a Sanhaja Berber dynasty from what is now Algeria which ruled the central Maghreb from 972 to 1014 and Ifriqiya (eastern Maghreb) from 972 to 1148.

Descendants of Ziri ibn Manad, a military leader of the Fatimid Caliphate and the eponymous founder of the dynasty, the Zirids were emirs who ruled in the name of the Fatimids. The Zirids gradually established their autonomy in Ifriqiya through military conquest until officially breaking with the Fatimids in the mid-11th century. The rule of the Zirid emirs opened the way to a period in North African history where political power was held by Berber dynasties such as the Almoravid dynasty, Almohad Caliphate, Zayyanid dynasty, Marinid Sultanate and Hafsid dynasty.

Under Buluggin ibn Ziri the Zirids extended their control westwards and briefly occupied Fez and much of present-day Morocco after 980, but encountered resistance from the local Zenata Berbers who gave their allegiance to the Caliphate of Cordoba. To the east, Zirid control was extended over Tripolitania after 978 and as far as Ajdabiya (in present-day Libya). One member of the dynastic family, Zawi ibn Ziri, revolted and fled to al-Andalus, eventually founding the Taifa of Granada in 1013, after the collapse of the Caliphate of Cordoba. Another branch of the Zirids, the Hammadids, broke away from the main branch after various internal disputes and took control of the territories of the central Maghreb after 1015. The main branch of the Zirids, also called the Badisides, occupied only Ifriqiya between 1048 and 1148. They were based in Kairouan until 1057, when they moved the capital to Mahdia on the coast. The Zirids of Ifriqiya also intervened in Sicily during the 11th century, as the Kalbids, the dynasty who governed the island on behalf of the Fatimids, fell into disorder.

The Zirids of Granada surrendered to the Almoravids in 1090, but the Badicides and the Hammadids remained independent during this time. Sometime between 1041 and 1051 the Zirid ruler al-Mu'izz ibn Badis renounced the Fatimid Caliphs and recognized the Sunni Muslim Abbasid Caliphate. In retaliation, the Fatimids instigated the migration of the Banu Hilal tribe to the Maghreb, dealing a serious blow to Zirid power in Ifriqiya. In the 12th century, the Hilalian invasions combined with the attacks of the Normans of Sicily along the coast further weakened Zirid power. The last Zirid ruler, al-Hasan, surrendered Mahdia to the Normans in 1148, thus ending independent Zirid rule. The Almohad Caliphate conquered the central Maghreb and Ifriqiya by 1160, ending the Hammadid dynasty in turn and finally unifying the whole of the Maghreb.

The Zirids were Sanhaja Berbers, from the sedentary Talkata tribe, originating from the area of modern Algeria. In the 10th century this tribe served as vassals of the Fatimid Caliphate, an Isma'ili Shi'a state that challenged the authority of the Sunni Abbasid caliphs. The progenitor of the Zirid dynasty, Ziri ibn Manad (r. 935–971) was installed as governor of the central Maghreb (roughly north-eastern Algeria today) on behalf of the Fatimids, guarding the western frontier of the Fatimid Caliphate.

With Fatimid support Ziri founded his own capital and palace at 'Ashir, south-east of Algiers, in 936. He proved his worth as a key ally in 945, during the Kharijite rebellion of Abu Yazid, when he helped break Abu Yazid's siege of the Fatimid capital, Mahdia. After playing this valuable role, he expanded 'Ashir with a new palace circa 947. In 959 he aided Jawhar al-Siqili on a Fatimid military expedition which successfully conquered Fez and Sijilmasa in present-day Morocco. On their return home to the Fatimid capital they paraded the emir of Fez and the "Caliph" Ibn Wasul of Sijilmasa in cages in a humiliating manner. After this success, Ziri was also given Tahart to govern on behalf of the Fatimids. He was eventually killed in battle against the Zanata in 971.

When the Fatimids moved their capital to Egypt in 972, Ziri's son Buluggin ibn Ziri (r. 971–984) was appointed viceroy of Ifriqiya, spawning a dynasty whose rulers held the title of amir. Buluggin's position was confirmed on 2 October 972 at Sardaniya, a place outside Kairouan where the Fatimid caliph al-Mu'izz was preparing for his departure to Egypt. On 20 December 972, Buluggin took up residence in Sabra al-Mansuriyya, the Fatimid caliph's former palace-city just outside the walls of Kairouan, where his successors continued to reside until the mid-11th century. Buluggin spent much of his time in the west, however. From 974 onward he entrusted the governance of Ifriqiya to Abd Allah ibn Muhammad al-Katib, a secretary with whom he replaced the Fatimid-appointed secretary, Ziyadat Allah. In 974 or 977–978 (364 or 367 AH), he founded another capital and palace complex in Ashir, next to his father's foundation, which he favoured over Kairouan. Ashir continued to be the capital of the Zirids in the central Maghreb, while Kairouan was the capital of Ifriqiya.

Buluggin soon led a new expedition west and by 980 he had conquered Fez and most of the western Maghreb (present-day Morocco), which had previously been retaken by the Umayyads of Cordoba in 973. He also led a successful expedition to Barghawata territory, from which he brought back a large number of slaves to Ifriqiya. In 978 the Fatimids also granted Buluggin overlordship of Tripolitania (in present-day Libya), allowing him to appoint his own governor in Tripoli. In 984 Buluggin died in Sijilmasa from an illness and his successor decided to abandon Morocco in 985.