Muhammad-Amin al-Imami al-Khu'i (Arabic: محمد أمين الإمامي الخوئي, romanized: Muhammad Amīn al-Imāmī al-Khūʾī), honorifically titled as Sadr al-Islam (Arabic: صدر الإسلام, romanized: Ṣadr-al-Islām; 1885 – June 1948) was an Iranian Ja'fari jurist and writer.
An Azeri-Asadi by ancestry, Najafi by birth and Khoei by origin, he was recognized as a first-class mujtahid of Tehran from 1920 to the 1940s, and played an effective role in post-constitutional years.
A well-known religious historian and author of many fiqh-related works in Arabic and Persian, however, most have remained as handwritten.
He traces his paternal lineage to Habib ibn Muzahir Al-Asadi, and maternal to Al-Hurr Al-Riyahi, who she was a daughter of Hussein Khan Donboli.
When he reached the age of majority, he began his Islamic education, such as logic, literary sciences and jurisprudence with the scholars of Khoy, including his father and maternal uncle.