Lustration in Central and Eastern Europe is the official public procedure of scrutinizing a public official or a candidate for public office in terms of their eventual past role as a witting confidential collaborator (informant) of relevant former communist secret police, an activity widely condemned by the public opinion of those states as morally corrupt due to its essential role in suppressing political opposition and enabling persecution of dissidents. Surfacing of evidence for such a past activity typically inflicts severe reputation damage to the person concerned. It should not be confused with decommunization which is the process of barring former communist regular officials from public offices as well as eliminating communist symbols.

The principle of non-retroactivity means that a past role of a confidential collaborator (informant) is alone as such inadmissible from the beginning for criminal prosecution or conviction, thus, lustration allows at least to bring such past collaborators to moral responsibility by making the public opinion aware of the established outcomes through their free dissemination. Another motivation was the fear that undisclosed past confidential collaboration could be used to blackmail public officials by foreign intelligence services of other former Warsaw Pact allies, in particular Russia.

Depending on jurisdiction, either every positive result or only the one obtained regarding a person who falsely declared otherwise, may trigger consequences varying greatly among jurisdictions, ranging from mere infamy to purging the person from office and a 10-year exclusion from holding public offices. Various forms of lustration were employed in post-communist Europe.