In positive psychology, a flow state, also known colloquially as being in the zone, is the mental state in which a person performing some activity is fully immersed in a feeling of energized focus, full involvement, and enjoyment in the process of the activity. In essence, flow is characterized by the complete absorption in what one does, and a resulting transformation in one's sense of time. Flow is the melting together of action and consciousness; the state of finding a balance between a skill and how challenging that task is. It requires a high level of concentration; however, it should be effortless. Flow is used as a coping skill for stress and anxiety when productively pursuing a form of leisure that matches one's skill set.

Named by the psychologist Mihály Csíkszentmihályi in 1970, the concept has been widely referred to across a variety of fields (and is particularly well recognized in occupational therapy), though the concept has been claimed to have existed for thousands of years under other names.

The flow state shares many characteristics with hyperfocus. However, hyperfocus is not always described in a positive light. Some examples include spending "too much" time playing video games or becoming pleasurably absorbed by one aspect of an assignment or task to the detriment of the overall assignment. In some cases, hyperfocus can "capture" a person, perhaps causing them to appear unfocused or to start several projects, but complete few. Hyperfocus is often mentioned "in the context of autism, schizophrenia, and attention deficit hyperactivity disorder – conditions that have consequences on attentional abilities."