Sayyid Abu l-Ḥasan al-Isfahānī (b. 1867 - d. 1946) was a great Twelver faqih and Marja' and the writer of Wasilat al-Najat and Sirat al-Najat. He was the special student of Akhund Khurasani. After the demise of Na'ini and Ha'iri Yazdi in 1936 and Aqa Diya' 'Iraqi in 1942, he became the only Shi'a authority in the most parts of the Shi'a world.
Like Akhund Khurasani, he believed in constitutional government and limiting the power of dictatorship. Throughout his life, he used to take position on political affairs especially on the Constitutional Movement in Iran. Moreover, even his demise sparked a political movement; According to some sources, the large attendance of people at his funeral ceremony, in November 1946, had a significant role in the failure of democratic movement in Azerbaijan.
One of the most important events during Sayyid Abu l-Hasan's life was the murder of his son, Sayyid Hasan. Sayyid Hasan, who submitted the requests of financial help to his father requested financial help for people from his father, was murdered in 1930. However, Sayyid Abu l-Hasan Isfahani forgave the murderer.
Some of his famous teachers are, Mulla Muhammad Kashani, Sayyid Muhammad Baqir Durchi'i, Jahangir Khan Qashqa'i, Mirza Habib Allah Rashti, Sayyid Muhammad Kazim Tabataba'i Yazdi, and Fath Allah Shari'at Isfahani.