The son of Rabbi Isaac Halevi Herzog, Chaim grew up in Dublin before immigrating with his family to Palestine in 1935. The following year he joined the Haganah, the pre-Israel Jewish defense forces. Herzog later returned to Britain, studying law at the University of London, and served in the British army during World War II. In 1947 he rejoined the Haganah, and with the formation of Israel in 1948, Herzog fought against neighbouring Arab countries in the first Arab-Israeli war (Arab-Israeli wars) and was named head of the country's military intelligence, a position he held until 1950 and again from 1959 to 1962. He rose to the rank of major general before retiring from the army in 1962 to practice law and pursue business ventures. With a series of radio broadcasts during the Arab-Israeli Six-Day War (1967), Herzog became one of the country's foremost political and military commentators, and he was appointed the first military governor of the West Bank after its capture during that conflict. As ambassador to the United Nations (1975–78), he drew international attention for his passionate, though unsuccessful, campaign to defeat the resolution that equated Zionism with racism.

In 1981, as a member of the Israel Labour Party, Herzog was elected to the Knesset (parliament). Two years later he was nominated for president, a largely ceremonial post. Although the rival Likud Party (Likud) controlled the Knesset, Herzog's widespread popularity led to his narrow victory. Once in office, he increased the role of the president. Herzog traveled abroad and spoke before numerous foreign governments, improving Israel's international image. He stressed tolerance, supporting greater rights for the Druze and other Arabs, and was an outspoken critic of the country's electoral system. In 1988 he ran unopposed in his bid for reelection, winning a second term, the maximum allowed under Israeli law. A noted author, Herzog wrote extensively on Israeli history. His autobiography, Living History: A Memoir, was published in 1996.