thumb|right|200px|Chaim Nahum with President [[Muhammad Naguib in 1953]]
Chaim (Haim) Nahum Effendi (; ; ) (1872–1960) was a Turkish Jewish scholar, jurist, and linguist of the early 20th century.
He served as the Grand Rabbi of the Ottoman Empire.
History
He was born in 1872 in Manisa, Turkey. He was sent by his parents to a yeshiva in Tiberias, after which he studied at a French lycée for his secondary education and obtained a degree in Islamic law Istanbul. Thereafter, he attended a rabbinical academy in Paris, from which he received his semicha. At the same time, he studied linguistics, history, and philosophy at the Sorbonne's School of Oriental Languages.
Upon his return to Constantinople, Nahum occupied various teaching positions, including at the Turkish military academy. While there, he became acquainted with many of the leaders of the Young Turk movement, who gained power in 1908.
In 1909 Nahum succeeded Moses Levi as Hakham Bashi, or chief rabbi, of the Ottoman Empire. "Nahum invested much effort in the restoration of communal institutions. He found a fervent advocate in the person of David Fresko, the editor of El Tiempo," a Ladino newspaper who politically supported the positions of Turkish reformers. During World War I he strove to be appointed as the Ambassador of the Ottoman Empire to the United States but did not get the position.