Muhammad ibn Falah (1400 in Wasit, Iraq – 1461 in Hoveizeh, Iran) was an Iraqi-born theologian who founded the Musha'sha'iya, a Shi'a sect.
He received his theological education in the city of al-Hillah, and there came to believe himself to be the earthly representative of Imam Ali and the Mahdi.
He was later denounced as a Kafir (non-muslim) by the Muslim establishment.
He was believed to have been descended from the seventh Shi'a Imam, Musa al-Kazim.
Upon his death, his son, Ali ibn Muhammad Musha'sha'iya, took over as leader of the sect, which began a dynastic line of succession.