Alid dynasties of northern Iran or Alavids (Persian: علویان طبرستان).

In the 9th–10th centuries, the northern Iranian regions of Tabaristan, Daylam and Gilan, sandwiched between the Caspian Sea and the Alborz range, came under the rule of a number of Arab Alid dynasties, espousing the Zaydi branch of Shia Islam.

The second period of the Alid emirate was plagued by internal dissensions and power struggles between the two branches, and ended in the second conquest of the region by the Samanids in 928.

Subsequently, some of the soldiers and generals of the Alavids joined the Samanids, among them Mardavij, founder of the Ziyarid dynasty, and the three sons of Buya (Ali, Hassan and Ahmad), founders of the Buyid dynasty.

Local Zaydi rulers survived in Daylam and Gilan until the 16th century.