An oracle is a person or thing that provides insight, wise counsel, or prophetic predictions, most notably including precognition of the future, inspired by deities. The word oracle comes from the Latin verb "to speak" and properly refers to the priest or priestess uttering the prediction. In extended use, oracle may also refer to the site of the oracle, and to the oracular utterances themselves.

Oracles were thought to be portals through which the gods spoke directly to people. In ancient times, an oracle was someone who offered advice or a prophecy thought to have come directly from a divine source. The most important oracles of Greek antiquity were Pythia (priestess to Apollo at Delphi), and the oracle of Dione and Zeus at Dodona in Epirus.

In modern usage, any good source of information can be called an oracle. An example of this usage is when someone is considered an oracle of pop culture, meaning they are an authoritative or wise expression or answer on the topic.