Polygamy is the act of being married to more than one spouse at a time. In the Bible this usually takes place with men being married to more than one wife. This started with Lamech of the lineage of Cain, who married Adah and Zillah, and has occasionally been performed by various people of the Messianic lineage and of the children of Israel, with Abraham, Jacob, King David, and Solomon being prime examples. While the Bible doesn't outright refer to polygamy as sin, in the New Testament, polygamy has been discouraged in favor of monogamy, as Paul the apostle in his letters to Timothy and Titus said that a man who seeks after the position of a bishop (also translated as elder or overseer) or a deacon must be the husband of only one wife.

In the Left Behind series, the African tyrant Rehoboth, who was the subpotentate of the United African States, is said to be married to multiple wives, who were all murdered along with their children by Global Community forces.

Technically speaking, Jesus Christ Himself is also a polygamist of sorts, having married the multiple children of God that make up the Church during the time of the Tribulation.