Born in the Belorussian town of Mir as Shneur Zalman Rubashov, he became active in the Po'alei Zion movement, organizing Jewish self­defense units during the 1905 revolution. He was one of the founders of the Zionist Labor Movement (1916) and of He­Halutz (Pioneers of Zion) in Germany.

Shazar settled in Palestine in 1924. He became a member of the secretariat of the Histadrut (General Federation of Labor) and joined the editorial staff of its daily paper Davar. He was a member of the Jewish Agency delegation to the United Nations General Assembly in 1947. Afer his election to the First Knesset, he became Israel's first Minister of Education and Culture (1949­1951). He became a member of the Jewish Agency Executive (1952), and from 1956 to 1960 was acting chairman of the Agency's Jerusalem Executive.

In 1963, Shazar succeeded Yitzhak Ben­Zvi as President of the State of Israel, and in was reelected for a second five­year term in 1968.

In addition to his political activity, Shazar was a scholar and author. His literary work took many forms, from poetry and autobiographical fiction to scholarly treatises and published articles, in both Hebrew and Yiddish.