Yousef Hamadani Cohen, the spiritual leader of Iran's tiny Jewish community, died at the weekend at the age of 100, media reported on Monday.
English-language Press TV said Cohen had been ill for several years, and that he was buried on Sunday in Tehran.
Fars news agency said Cohen had been the chief rabbi of the Jewish community in Iran since 1994.
Mashallah Golestani Nejad took over the position following his death, said Press TV.
State news agency IRNA said Cohen was 100 years old when he died at the weekend.
It quoted an MP who represents the Jewish community, Siamak Moreh Sedgh, as saying that he gave up his main duties in 2006 as he suffered from Alzheimer's.
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According to a 2011 census, some 8,750-20,000 Jews live in Iran, compared to 80,000-1000,000 before the 1979 Islamic revolution.
Jews -- who live mostly in Tehran, Isfahan and Shiraz -- are recognised as a religious minority along with Christians and Zoroastrians.
The Jewish community has a representative in parliament and appears to be well integrated in a society dominated by Muslims.
It operates schools, a library and a hospital -- which relies in part on public funds -- in Tehran.
The election of President Hassan Rouhani in June 2013, a reputed moderate, raised hopes among the community for an improvement of their standing.
His hardline predecessor, Mahmoud Ahmadinejad, gave regularly anti-Israeli tirades during his two terms in office.
Both Rouhani and Foreign Minister Mohammad Javad Zarif congratulated the Jewish community for their New Year in early September. They have also condemned the Holocaust.