James S. Donnelly, Jr. (born 1943) is a modern British and Irish historian. Donnelly is a Professor Emeritus of History at the University of Wisconsin-Madison. One of the most prolific and wide-ranging historians of Ireland, he has also been a leading figure in the promotion of Irish studies in North America. Donnelly is a former president of the American Conference for Irish Studies, and a current co-editor of the journal Éire-Ireland. His first book, The Land and the People of Nineteenth-Century Cork, was awarded the Herbert Baxter Adams Prize of the American Historical Association.