Jacob de Haas (* 13th August 1872 in London; † 21st March 1937 in New York City) was a BritishHasidic Jew, a journalist and an early leader of the Zionist movement, who propagated the movement in the United States.
He moved to the United States in 1902. Theodor Herzl had suggested to Richard Gottheil that he hire de Haas as the new secretary of the Federation of American Zionists (FAZ) to replace Stephen Samuel Wise. De Haas assumed the leadership of the fragmented American Zionist movement. One of his best known accomplishments was his befriending of Louis Brandeis, the best known, and admired secular Jew in America. De Haas introduced Brandeis to the ideas of Theodor Herzl and ideals of Zionism. After a relatively short period of examination and self-examination, Louis Brandeis became an ardent, committed Zionist in 1908. More importantly, Brandeis, would head the FAZ and the American Zionist movement by 1912.