Al-Hadi ila’l-Haqq Yahya (859 – August 19, 911) is a religious and political leader on the Arabian Peninsula.

He is the first Zaydiyya imam who rules over portions of Yemen, in 897-911, and is the ancestor of the Rassid Dynasty which will hold intermittent power in Yemen until 1962.

The Hadawiyya school of Islamic law, the only authoritarian one for the Zaydiyya, stems from him.