Vaticinium ex eventu ("Prophecy from the event") is a technical theological or historiographical term referring to a prophecy written after the author already had information about the events he was "foretelling". The text is written so as to appear that the prophecy had taken place before the event.

There is no agreement how much of Biblical prophecy falls into this category. From the point of view of the devout followers of Bible-based religions (Christianity and Judaism), all or almost all of the prophecies are actually prophecies made before the event. Critical exegetes are generally agreed that certain prophecies, such as Jesus' prophecy of the destruction of the Temple of Jerusalem (Luke 21:24), were inserted into the text after the fact. This is one of the primary data used for the dating of the Gospels by these scholars. On the other hand, some of these critical scholars hold that at least part of Jesus' prediction of his own death and resurrection (Mark 8:31, for example) could plausibly have been made before his death.

The Sibylline oracles are held to be vaticinia ex eventu written in imitation of the Roman Sibylline Books, from the later Hellenistic era to Late Antiquity, first by Jews of Alexandria and later by Christians throughout the Roman world.

In Hinduism, the prophet Madhva made a vaticinium ex eventu in the thirteenth century when he applied a Vedic prophecy to himself, declaring himself to be an incarnation.

The Book of Mormon, at least from the viewpoint of those outside the Latter-Day Saints religions, contains many vaticinia ex eventu, such as the discovery of The Americas by Christopher Columbus or the foretelling of the founder, Joseph Smith Jr..

Many of the alleged prophecies of Nostradamus have the characteristics of a vaticinium ex eventu, as Nostradamus supporters often offer alternative translations and interpretations of his prophecies after major events to cause the appearance of accurate prophecy.