Al-Husayn Husam al-Din ibn Idris Imad al-Din was the 21st of Tayyibi Isma'ilis in Yemen from 1512 to 1527.
He succeeded his brother al-Hasan Badr al-Din II in 1512, and held the post until his death in 1527, when he was succeeded by his son Ali Shams al-Din III.