Event can refer to many things such as:
* A phenomenon, any observable occurrence, or an extraordinary occurrence
A type of gathering:
* A ceremony, for example, a marriage
* A competition, for example, a sports competition
* A convention (meeting)
* A happening, a performance or situation meant to be considered as art
* A festival, for example, a musical event
* A media event, a happening that attracts coverage by mass media
* A party
* A sporting event
In science, technology, and mathematics:
* Event (computing), a software message indicating that something has happened, such as a keystroke or mouse click
* Event, Particle accelerator, experiments which produce high energy (Electron volt|MeV, GeV, and TeV) subatomic particle collisions
* Event (probability theory), a set of outcomes to which a probability is assigned
* Event (UML), in Unified Modeling Language, a notable occurrence at a particular point in time
* Event chain methodology, in project management
* Event (relativity), a point in space at an instant in time, i.e. a location in spacetime
* Event horizon, a boundary in spacetime, typically surrounding a black hole, beyond which events cannot effect an exterior observer
* Extinction event, a sharp decrease in the number of species in a short period of time
* Celestial event, an astronomical phenomenon of interest
In philosophy:
* Event (philosophy), an object in time, or an instantiation of a property