James S. Donnelly Jr. (born 1943) is emeritus professor of history at the University of Wisconsin–Madison, where he specialised in nineteenth-century Irish history.
He is a leading figure in the field 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 research on An Gorta Mór (1845–51) made him a well-known historian in the debate on whether The Great Hunger was genocide or not.
[1] He has cooperated with Dr. Andy Bielenberg of University College Cork in compiling a digital profile of casualties in Cork during the Irish War of Independence.