Laqueur was born in Breslau, Lower Silesia, Prussia (modern Wrocław, Poland), into a Jewish family. In 1938, he left Germany for the British Mandate of Palestine. His parents, who were unable to leave, became victims of the Holocaust.

Laqueur lived in Israel from 1938 to 1953. After one year at the Hebrew University of Jerusalem, he joined a Kibbutz and worked as an agricultural laborer from 1939 to 1944. In 1944, he moved to Jerusalem, where he worked as a journalist until 1953, covering Palestine and other countries in the Middle East.

Since 1955 Laqueur has lived in London. He was founder and editor, with George Mosse, of the Journal of Contemporary History and of Survey from 1956 to 1964. He was also founding editor of The Washington Papers. He was Director of the Institute of Contemporary History and the Wiener Library in London from 1965 to 1994. From 1969 he was a member, and later Chairman (until 2000), of the International Research Council of the Center for Strategic and International Studies, Washington. He was Professor of the History of Ideas at Brandeis University from 1968 to 1972, and University Professor at Georgetown University from 1976 to 1988. He has also been a visiting professor of history and government at Harvard, the University of Chicago, Tel Aviv University and Johns Hopkins University.

Laqueurs main works deal with European history in the 19th and 20th centuries, especially Russian history and German history, as well as the history of the Middle East. The topics he has written about include the German Youth Movement, Zionism, Israeli history, the cultural history of the Weimar Republic and Russia, Communism, the Holocaust, fascism, and the diplomatic history of the Cold War. His books have been translated into many languages, and he was one of the founders of the study of political violence, guerrilla warfare and terrorism. His comments on international affairs have appeared in many American and European newspapers a