Onlooker

An onlooker is a person who observes an event, situation, or activity without taking part in it. The term is commonly used to describe a bystander, watcher, or observer who is physically present but not involved in the action.

In everyday usage, onlookers are distinguished from participants and from witnesses who actively testify or intervene. In journalism and reporting, the label emphasizes a passive role, noting that the onlooker saw what occurred without influencing its course.

Related terms include bystander, observer, spectator, and witness. In psychology and social behavior research, the presence of onlookers can influence responses, a dynamic that relates to the bystander effect.