There are 1 book by Mary Celine O'Brien on BookOrb. A strong starting point is I charge each of you (1966). The bibliography below is in publication order, with series grouped in reading order.
Standalone books
Frequently asked questions
How many books has Mary Celine O'Brien written?
BookOrb lists 1 book by Mary Celine O'Brien.
Where should I start with Mary Celine O'Brien?
A good starting point is I charge each of you (1966).
What is the Mary Celine O'Brien books in order list?
In publication order: 1. I charge each of you (1966).