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 Iowa, perjury is defined as knowingly making a false statement under oath or affirming the truth of a statement previously made when the statement is material and the person does not believe it to be true. This is outlined in the Iowa Code under Chapter 720, which deals with false public statements. Perjury in Iowa is considered a Class D felony, which can result in a fine and/or imprisonment. Suborning perjury, or persuading another person to commit perjury, is also a criminal offense and is treated with similar severity as perjury itself. At the federal level, perjury is governed by 18 U.S.C. §1621, and like in Iowa, it involves willfully making false statements under oath in federal proceedings. The federal law also treats perjury as a serious offense, with penalties that can include fines and imprisonment. Both state and federal laws aim to uphold the integrity of the judicial process by deterring and punishing false statements.