Chaim Azriel Weizmann (November 27, 1874 – November 9, 1952) was a Russian-born biochemist, chemist, and prominent Zionist leader who played a pivotal role in the establishment of the State of Israel and became its first President. Born in the Jewish village of Motol near Pinsk in the Russian Empire (now Belarus), he was the third of fifteen children in a modest family. Demonstrating early intellectual promise amid widespread antisemitism, Weizmann pursued higher education in chemistry and biochemistry across Europe and eventually settled in Britain, where he became a respected academic and inventor. Notably, he developed a bacterial process for acetone production during World War I, supporting the Allied war effort and increasing his influence.

His Zionist activism began in youth, and he served as president of the World Zionist Organization during two terms (1921–1931 and 1935–1946). Weizmann's diplomatic skills were instrumental in securing the 1917 Balfour Declaration, in which the British government expressed support for a Jewish national home in Palestine, as well as garnering international support for Zionism. After World War I, he advocated for Jewish immigration and statehood, deftly navigating complex international relations. In 1948, he successfully lobbied for U.S. recognition of Israel and became Israel’s first president on February 16, 1949, serving until his death. Although his presidency initially had mainly ceremonial powers, it symbolized the realization of Zionist aspirations.

Weizmann also founded the Weizmann Institute of Science in Rehovot, Israel, promoting scientific advancement. Throughout his life, he balanced scientific innovation with political advocacy, authored an autobiography, and taught at universities. Married to Vera Chatzman in 1906, with whom he had two sons, his family life was intertwined with his public duties. Chaim Weizmann died at his home in Rehovot, leaving a legacy bridging science, diplomacy, and Jewish statehood.