There are 3 books by Pius O'Brien on BookOrb. A strong starting point is The Sisters of Mercy of Ennis (1992). The bibliography below is in publication order, with series grouped in reading order.
Standalone books
Frequently asked questions
How many books has Pius O'Brien written?
BookOrb lists 3 books by Pius O'Brien.
Where should I start with Pius O'Brien?
A good starting point is The Sisters of Mercy of Ennis (1992).
What is the Pius O'Brien books in order list?
In publication order: 1. The Sisters of Mercy of Ennis (1992), 2. The Sisters of Mercy of Birr and Nenagh (1994), 3. The Sisters of Mercy of Kilrush and Kilkee (1997).