Abbas, born in the Arab-Jewish town of Zefat (Ẕefat), fled with his family to Syria during the 1948 Arab-Israeli war (Arab-Israeli wars). Despite the family's refugee status, Abbas earned a law degree from the University of Damascus. In the late 1950s Abbas was one of the founders of Fatah, which spearheaded the Palestinian armed struggle and came to dominate the Palestine Liberation Organization (PLO). As head of the PLO's international department in the late 1970s, Abbas was instrumental in forging contacts with Israeli peace groups. In 1982 Abbas was awarded a doctorate in history from Moscow State University; his dissertation, which examined Nazism and Zionism, later was decried by Jewish groups as a work of Holocaust denial, and in the 1990s he distanced himself from some of its more controversial elements.

In the early 1990s Abbas shaped Palestinian negotiating strategy at both the peace conference in Madrid (1991) and in secret meetings with the Israelis in Norway. Through the resulting Oslo Accords (1993), Israel and the Palestinians extended mutual recognition to each other, and Israel ceded some governing functions in the West Bank and Gaza Strip to a Palestinian Authority. Abbas was a senior member of the Palestinian delegation to the Camp David peace talks in July 2000; he adamantly rejected Israel's peace offer but opposed the violent Palestinian uprising called the intifāḍah (Arabic: “shaking off”) that followed. In 2003, after intense international pressure, Abbas was installed as Palestinian prime minister as an effort to circumvent ʿArafāt (Arafāt, Yāsirʿ), who was considered an impediment to peace by Israel and the United States. Abbas quickly renounced terrorism, called for an end to the intifāḍah against Israel, and resolved to create a single Palestinian armed force, but he soon resigned from office, claiming he had been undermined by Israel, the United States, and ʿArafāt.

Following ʿArafāt's death in November 2004, Abbas was named head of the PLO. In January 2005 he easily won the election to succeed ʿArafāt as president of the Palestinian Authority, garnering more than 60 percent of the vote.