Al-Malik al-Mas‘ūd Ṣalāḥ al-Dīn Abū al-Muẓaffar Yūsuf ibn Muḥammad (Arabic: الملك المسعود صلاح الدين أبو المظفر يوسف بن محمد; 1201–1229) was the sixth and final Ayyubid ruler of Yemen, from 1215 to 1229.