PYTHIA is a computer simulation program for particle collisions at very high energies (see event (particle physics)) in particle accelerators.

The Pythia (, ), commonly known as the Oracle of Delphi, was the name of any priestess throughout the history of the Temple of Apollo at Delphi, which was located on the slopes of Mount Parnassus, beneath the Castalian Spring  on the north shore of the Corinthian Gulf in Greece. Each new priestess was selected after the death of the current priestess, and after the legendary death of a man, was always a woman, who surrendered her name and position upon becoming the oracle. The Pythia, established in the 8th century BC, was widely credited for her prophecies inspired by being filled by the spirit of God (or enthusiasmos) by the God  Apollo. The Delphic oracle may have been present in some form in Late Mycenaean times, from 1400 BC and was abandoned, and there is evidence that Apollo took over the shrine from an earlier dedication to Gaia. The last recorded response of the oracle was given about 395 A.D. to Emperor Theodosius I, after he had ordered pagan temples to cease operation.