Sayyid Muhammad bin Fadlallah al-Sarawi (Arabic: محمد بن فضل الله الساروي, romanized: Muḥammad bin Faḍlallāh al-Sārawī, Persian: محمد بن فضل‌الله ساروی, romanized: Muhammad ben Fazlollāh Sārawī), honorifically titled as Thiqat al-Islam (Arabic: ثقةالاسلام), also known as Muhammad Thiqat al-Islam (Arabic: محمد ثقة الإسلام, romanized: Muḥammad Thiqat al-Islām; c. 1880 – May 1924) was an Iranian-Iraqi Ja'fari jurist, writer and poet.

He first started his religious educations with his father then moved to Ottoman Iraq and studied from ulema of Najaf and Samarra, such as Mirza Shirazi.

As a Twelver Shia mujtahid, he settled in Najaf from 1901 until his death, left behind two poetry collections and many books on fiqh, most of them are manuscript.

[4] After finishing his religious education, he returned to Iran to promote da'wah, but failed due to poor public acceptance and produced some antagonism.

[4] In Najaf, he continued his religious scholarly activities, focused on reading, researching, writing, and composing poetry in both Arabic and Persian languages.