Peggy O'Brien was educated at Mount Holyoke (B.A.), University College, Dublin (M.A.) and Trinity College, Dublin (Ph.D.). She taught in Ireland, at Trinity College in the English Department, for seventeen years before returning to the United States, first as a Five College professor in this area and then in 1987 as a member of the English Department. She offers regular course at all levels in Irish Literature, specializing in poetry. She has taught single author, honors classes on Seamus Heaney and W.B. Yeats and a graduate seminar on "Poetry and Politics in Ireland." Almost every year she offers an "Introduction to Twentieth Century Irish Literature" for General Education credit.
She is the editor of the Wake Forest Book of Irish Women's Poetry:1969-2000 and publishes regular essays on contemporary, Irish poetry. She is currently completing a book on Irish literature from 1800 to the present centered on a famous, ancient site of pilgrimage in Ireland, Lough Derg. She is also a published poet.