There are 1 book by Wimpie O'Callaghan on BookOrb. A strong starting point is Judgment of Gehenna (2013). The bibliography below is in publication order, with series grouped in reading order.
Standalone books
Frequently asked questions
How many books has Wimpie O'Callaghan written?
BookOrb lists 1 book by Wimpie O'Callaghan.
Where should I start with Wimpie O'Callaghan?
A good starting point is Judgment of Gehenna (2013).
What is the Wimpie O'Callaghan books in order list?
In publication order: 1. Judgment of Gehenna (2013).