The history of workplace deviance research has evolved from a focus on singular behaviors, such as theft or withdrawal in the 1970s and 1980s, to the broader focus on a range of behaviors in the 21st century. This more inclusive cluster of related “dark side” behaviors is made up of voluntary behaviors that violate significant organizational norms and in so doing threaten the well-being of an organization, its members, or both. Examples of behaviors that fall in this domain are employee theft and sabotage of organizational goods, services, data, customer lists, materials, working slow, calling in sick when you are not, bullying, harassment, discrimination, and gossip. Workplace deviance can be targeted at other individuals in the organization (coworkers, supervisors, subordinates) or at the organization itself, or both. Typically the actor’s perspective is considered, but other relevant views of the behavior include the supervisor/the organization, peers, customers, or other third parties. Many causes have been studied as sources of deviant workplace behaviors, for example personality characteristics such as neuroticism or low conscientiousness, modeling others’ behavior, experiences of injustice, uncertainty, lack of control or feelings of anger, frustration, and dissatisfaction. Nowadays, some researchers are returning to a focus on individual behaviors, or smaller clusters of behaviors such as sexual misconduct, gossip, and even constructive deviance, and the outcomes of workplace deviance on actors, targets, and observers are being investigated.