Sir Ian Kershaw is an English historian whose work has chiefly focused on the social history of 20th-century Germany. He is regarded by many as one of the world's foremost experts on Adolf Hitler and Nazi Germany, and is particularly noted for his biographies of Hitler.

He was a follower of the German historian Martin Broszat, and until his retirement, he was a professor at the University of Sheffield. Kershaw has called Broszat an "inspirational mentor" who did much to shape his understanding of Nazi Germany. Kershaw served as historical adviser on numerous BBC documentaries, notably The Nazis: A Warning from History and War of the Century. He taught a module titled "Germans against Hitler."

Ian Kershaw studied at Liverpool (BA) and Oxford (D. Phil). He was a lecturer first in medieval, then in modern, history at the University of Manchester. In 1983-4 he was Visiting Professor of Modern History at the Ruhr University in Bochum, West Germany. From 1987 to 1989 he was Professor of Modern History at the University of Nottingham, and since 1989 has been Professor of Modern History at Sheffield. He is a fellow of the British Academy, of the Royal Historical Society, of the Wissenschaftskolleg zu Berlin, and of the Alexander von Humboldt-Stiftung in Bonn. He retired from academic life in the autumn semester of 2008.