Jury tampering is the crime of unduly attempting to influence the composition and/or decisions of a jury during the course of a trial.

The means by which this crime could be perpetrated can include attempting to discredit potential jurors to ensure they will not be selected for duty. Once selected, jurors could be bribed or intimidated to act in a certain manner on duty. It could also involve making unauthorized contact with them for the purpose of introducing prohibited outside information and then arguing for a mistrial.