Muslim dynasty that ruled Yemen in the period 819–1018 from its capital at Zabīd.

The ʿAbbāsid caliph al-Maʾmūn transferred the rule of Yemen to the Ziyād family to offset the intrigues of the ʿAlids—the Shīʿite opponents of the ʿAbbāsids—who had made southern Arabia their headquarters. The first Ziyādid, Muḥammad ibn Ziyād, firmly established himself along the Yemeni coast (Tihāmah) with the support of a Khorāsānian army and cavalry; he was also recognized by the tribal chiefs along the edges of the highlands. Ṣanʿāʾ (Sanaa) in the interior, however, remained under ʿAbbāsid control, and, when the Banū Yaʿfur—the pre-Islāmic nobility—set up an independent dynasty there in 859, they soon forced the Ziyādī ruler Ibrāhīm ibn Muḥammad (859–902) to cede territory in return for tribute. More territory, including Zabīd itself, was lost to the sectarian Qarmaṭians after Ibrāhīm's death, and records of his successor have been obscured. Abū al-Jaysh Isḥāq, however, restored Ziyādid power and territory in a celebrated reign (904–981).

In 989 the Ziyādid capital was seized and burned by the Banū Yaʿfur, and effective power passed from the Ziyādids to their Ethiopian slave-viziers. The Mamlūk (slave) al-Ḥusayn ibn Salāmah, who had preserved the kingdom from collapse after the Yaʿfurid attack, was succeeded by his slave Marjān, who divided the government of the kingdom between two other Mamlūks, the northern provinces falling to Najāḥ, the capital and southern regions coming under the rule of Nafīs. In 1018 the last Ziyādid ruler was murdered by Nafīs. Control of Zabīd finally fell to Najāḥ, however, and in 1022 the Najāḥids began their rule in Yemen.