Zayd ibn Ali (d. 740) was the son of the Fourth Shia Imam, Ali Zayn al Abidin. Zayd was thus the grandson of Husayn bin Ali.

Zayd led a rebellion against the unjust and unislamic attitude of Umayyads in the mid 8th century, renewing the hostilities that existed between the Umayyads and the Hashemites. Zayd was killed during fighting in 740.

After his death, some felt that he was the rightful sucessor to his father, rather than his half-brother Muhammad al-Baqir. Those who believe in this line of succession form the Zaidi sect within Shiism.