There are 1 book by Martin O'Brien on BookOrb. A strong starting point is Blood Counts (2010). The bibliography below is in publication order, with series grouped in reading order.
Standalone books
Frequently asked questions
How many books has Martin O'Brien written?
BookOrb lists 1 book by Martin O'Brien.
Where should I start with Martin O'Brien?
A good starting point is Blood Counts (2010).
What is the Martin O'Brien books in order list?
In publication order: 1. Blood Counts (2010).