The Oracle of Delphi was the oldest of the four Oracles controlled by Apollo. The only Oracle older was the Grove of Dodona (which was controlled by Rhea). The Oracle of Delphi was not only a location, but also a person. Those who sought the future would go to Delphi and ask the Oracle a question, and would receive an answer in the form of a prophecy. The prophecies were in verse and would be riddles of sorts which would have to be interpreted.
- The new Oracle of Delphi is located in Camp Half-Blood.
- The Priestess of the Oracle is called the Pythia. She channeled Apollo's power and spoke his prophecies.
- 'Python' means 'rotting'. Pythia comes from Python, since Python inhabited the cave of the Oracle when Leto was pregnant.
- Percy jokingly says Pythia could also mean the Priestess speaks a bunch of rot.
- The current Oracle is Rachel Elizabeth Dare.