German rabbi; born at Vienna in 1662; died at Gemund, Bavaria, in 1740. He resided for many years at Frankfort-on-the-Main, where he assisted Jair Ḥayyim Bacharach in preparing his responsa, "Ḥawwot Ya'ir," for publication, and edited the works of Gershon Ashkenazi—"'Abodat ha-Gershuni," responsa, and "Tif'eret ha-Gershuni," homilies, 1699. Hanau was for a time rabbi of Idstein, while living in Frankfort. In 1702 he was made district rabbi of the Palatinate, and took up his residence at Heidelberg. Seven years later, owing to the great influence which his brother Elhanan had with the margrave Wilhelm Friedrich, he was appointed district rabbi of Ansbach. Elhanan, however, soon fell into disgrace, and both brothers were thrown into prison; Hanau was accused of witchcraft on account of his cabalistic studies. For twenty-four years Hanau remained in jail, until an inundation threatened the safety of the prison, and the prisoners were removed. The city councilors, moved with compassion at the sight of the old man, obtained from the margrave his liberation.
During his stay in prison Hanau wrote an abstract of the first 189 sections of the Yoreh De'ah; a commentary on Psalm and Hallel, entitled "Dodi li-Ẓebi"; and a poem of thirty-two verses describing his life in prison. Hanau was antagonized by David Oppenheim,who, in his "Nish'al Dawid," severely criticized several of Hanau's decisions given at Heidelberg.