In law enforcement a sting operation is an operation designed to catch a person committing a crime. A typical sting will have a law-enforcement officer or cooperative member of the public go along with a criminal's actions (for example by purchasing drugs the criminal is selling) to gather evidence of the criminal's wrongdoing.

Law-enforcement may have to be careful not to provoke the crime. In common law jurisdictions, the defendant may invoke the defense of entrapment.

See also Operation Pin.