She has written extensively on Irish history, receiving many awards for her work. Particularly notable publications include her biography of Wolfe Tone (1989), and more recently Catholics of Ulster: a history (2000) and a biography of Robert Emmet (2003). Her research interests are political and cultural history, religious identities, eighteenth-century Ireland and France and the history of Ulster.
In 2005, Professor Elliott was invited to deliver the prestigious Ford Lectures at Oxford University on "Religion and Identity in Irish History" and is currently preparing them for publication.
In addition to her academic role Professor Elliott has also played an important role in the promotion of peace efforts in Northern Ireland. Notably serving on the Opsahl Commission in 1993 and co-writing its report, 'A Citizens' Inquiry'.
In October 2000 she was awarded an OBE for services to Irish Studies and the Northern Ireland peace process and in 2002 was elected a Fellow of the British Academy.