- Percy Jackson and the Lightning Thief
- Percy Jackson and the Sea of Monsters
- Percy Jackson and the Titan's Curse
- Percy Jackson and the Battle of the Labyrinth
- Percy Jackson and the Last Olympian
Since then, there have been new books added to the Percy Jackson universe but they are in separate series like the Heroes of Olympus series and the Trials of Apollo series.
However, there have been updates to the original Percy Jackson series including graphic novel adaptations, illustrated editions, anniversary editions, and more recently a Disney+ streaming series. There is no information currently available about a sixth book written in the original series format, but new developments can always happen in the future.
For the latest information on Rick Riordan's upcoming projects and publications, I recommend visiting his official website.