Instant replay or action replay is a video reproduction of something that recently occurred which was both shot and broadcast live.

The video, having already been shown live, is replayed in order for viewers to see again and analyze what had just taken place.

Some sports allow officiating calls to be overturned after the review of a play. Instant replay is most commonly used in sports, but is also used in other fields of live TV.

While the first near-instant replay system was developed and used in Canada, the first instant replay was developed and deployed in the United States.

Outside of live action sports, instant replay is used to cover large pageants or processions involving major dignitaries (e.g. monarchs, religious leaders such as the Catholic Pope, revolutionary leaders with mass appeal), political debate, legal proceedings (e.g. O.J. Simpson murder case), royal weddings, red carpet events at major award ceremonies (e.g. the Oscars), grandiose opening ceremonies (e.g. 2022 Winter Olympics opening ceremony), or live feeds to acts of terrorism currently in progress.

Instant replay is used because the events are too large to cover from a single camera angle, events are too fast moving to catch all the nuance on the first viewing, the high points of the event are surrounded by much of a muchness, or punditry is supplied to punch the event up, such as analyzing the daring plunge of a plunging neckline to the last revealing millimeter.

In media studies, the timing and length of the replay clips as well as the selection of camera angles is a form of editorial content with a large impact on how the audience perceives the events covered.

Because of the origin of television as a broadcast technology, a "channel" of coverage is traditionally a single video feed consumed in the same way by all viewers. In the age of streaming media, live current events can be accessed by the final viewer with multiple streams of the same content playing concurrently in different windows or on different devices, often with direct end-user control over rewinding to a past moment, as well as an ability to select accelerated, slow-motion or stop-action replay speed.

During the COVID-19 pandemic, many jurisdictions have daily or weekly public health announcements which are available on streaming services such as YouTube and Facebook in near real-time.

It is no longer difficult for the end viewer to linger over the portions which present novel information, such as updated results from daily case counts or new epidemiological models, and then to speed through the dull parts at accelerated playback speed. This can be framed as a novel media consumption modality of instantaneous time shifting.