There are 1 book by Howard O'Brien on BookOrb. A strong starting point is The Impulsive Imp (2007). The bibliography below is in publication order, with series grouped in reading order.
Standalone books
Frequently asked questions
How many books has Howard O'Brien written?
BookOrb lists 1 book by Howard O'Brien.
Where should I start with Howard O'Brien?
A good starting point is The Impulsive Imp (2007).
What is the Howard O'Brien books in order list?
In publication order: 1. The Impulsive Imp (2007).