Perjury is the criminal offense of making a false statement under oath—verbally or in writing—that the witness knows to be false and that is material to the proceeding in which the statement is made. And suborning perjury or subornation of perjury is the criminal offense of procuring the perjury of another person.

Perjury is a criminal offense under both state and federal laws and may be prosecuted as a misdemeanor or as a felony offense, depending on the state or federal jurisdiction, and whether there are any aggravating factors that increase the seriousness of the crime. Perjury laws are located in state statutes—often in the penal or criminal code—and the federal perjury law is located in the United States Code at 18 U.S.C. §1621.

In Wisconsin, perjury is considered a serious criminal offense. Under Wisconsin law, specifically section 946.31 of the Wisconsin Statutes, an individual commits perjury when they intentionally swear falsely or affirm untruthfully regarding a material matter in any judicial or other proceeding where an oath is required by law. This includes both verbal statements and written affidavits or declarations. Perjury is classified as a Class H felony in Wisconsin, which can result in significant penalties including fines and imprisonment. Additionally, subornation of perjury, which involves persuading or inducing another person to commit perjury, is also a criminal offense under Wisconsin law and carries similar penalties. At the federal level, perjury is governed by 18 U.S.C. §1621, and like Wisconsin law, it criminalizes the act of willfully making false statements under oath in federal proceedings. The federal statute also treats perjury as a felony, with potential penalties including fines and imprisonment.