Prof. Farrell's current project looks at the politics of public health in Victorian Belfast (1832-80), focusing on what societal responses to a variety of crises (cholera, the 'Blackstaff Nuisance', Famine) tell us about how Belfast men and women thought about what constituted 'public health' in the period. Prof. Farrell has published widely on 19th-century Irish history, especially relating to Ulster.

His research has focused on the interplay between religion and popular politics in modern Ireland. His first book, Rituals and Riots: Sectarian Violence and Political Culture in Ulster, 1784-1886, examined the relationships between Catholic/Protestant rioting and the emergence of a divided political culture in the north of Ireland. He has also co-edited two volumes of essays on aspects of the modern Irish experience (with Danine Farquharson and Michael de Nie) and co-authored a book (with his former Ph.D. student Mathieu Billings) entitled The Irish in Illinois. His latest book, Thomas Drew and the Making of Victorian Belfast, uses the public career of a populist Orange cleric to re-evaluate aspects of the history of nineteenth-century Belfast. He is currently working on two book projects: a synthetic essay on the challenge of sectarianism in nineteenth-century Ireland; and a research monograph on the Blackstaff Nuisance, a study of an environmental disaster in Victorian Belfast.. He is a former President of the American Conference for Irish Studies and currently an international representative for the Society for the Study of Nineteenth-Century Ireland. 

Prof. Farrell will be based in the Institute of Irish Studies, QUB, 15 April to 20 May 2025.