The user illusion is the illusion created for the user by a human–computer interface, for example the visual metaphor of a desktop used in many graphical user interfaces. The phrase originated at Xerox PARC.

Some philosophers of mind have argued that consciousness is a form of user illusion which argues that conscious experience does not expose objective reality, instead it provides a simplified version of reality that allows the user, humans, to make decisions and act in their environment, akin to a computer desktop. According to this picture, our experience of the world is not immediate, as all sensation requires processing time. It follows that our conscious experience is less a perfect reflection of what is occurring, and more a simulation produced unconsciously by the brain. Therefore, there may be phenomena that exist beyond our peripheries, beyond what consciousness could create to isolate or reduce them.

This notion is explored by Tor Nørretranders in his 1991 Danish book Mærk verden, issued in a 1998 English edition as The User Illusion: Cutting Consciousness Down to Size. He introduced the idea of exformation in this book. Philosopher Daniel Dennett has also embraced the view that human consciousness is a "user-illusion".