Cyrus Adler was born on September 13, 1863, in Van Buren, Arkansas.

He was an American educator, Jewish religious leader, librarian, editor, and scholar. He studied at the University of Pennsylvania (1883) and Johns Hopkins University (Oriental studies), where he became a Fellow in Semitic languages (1885-1887). There, he received the first American Ph.D. in Semitics, became an instructor in Semitic languages and was promoted to Associate Professor in 1890. In 1877, Adler was appointed assistant curator of the section of Oriental antiquities in the U.S. National Museum. He was a librarian at the Smithsonian Institution in Washington, D.C. (1892-1905). In 1895, he located Thomas Jefferson’s Bible and purchased it for the Smithsonian Institution from his great-granddaughter. He lectured on biblical archeology at the Jewish Theological Seminary in New York and was President of the American Jewish Historical Society. In 1900, he was elected a member of the American Philosophical Society. He founded the Jewish Welfare Board and served as President of Dropsie College for Hebrew and Cognate Learning (1908-1940) and Chancellor of the Jewish Theological Seminary of America. Adler was also a founding member of the Oriental Club of Philadelphia. He edited the Jewish Encyclopedia, the American Jewish Yearbook (1899-1905), and the Jewish Quarterly Review (1910-1940). Adler contributed to the New International Encyclopedia, the Journal of the American Oriental Society, the Proceedings of the American Philological Association, the Andover Review, Hebraica, and the Johns Hopkins University Circular. He was a part of the committee that translated the Jewish Publication Society version of the Hebrew Bible published in 1917. At the end of World War I, he participated in the Paris Peace Conference in 1919.

In 1905, he married Racie Friedenwal (1872–1952). He died on April 7, 1940, in Philadelphia, Pennsylvania.