Marriage—also known as matrimony or wedlock—is the legal and cultural process by which two people join their separate lives as one. The contractual rights and obligations of the parties to a marriage are generally defined by the state, as provided in the state’s statutes (often in the family code), unless otherwise agreed by the parties in a prenuptial or postnuptial agreement. Marriage is intended to last until death, but is often terminated sooner by separation or divorce.

In Iowa, marriage is recognized as a legal union between two individuals, which is regulated under the state's statutes, particularly within the Iowa Code. The rights and obligations of the parties in a marriage are defined by these laws, which cover aspects such as property rights, spousal support, and inheritance. Couples in Iowa have the option to enter into prenuptial or postnuptial agreements to alter or specify the terms of their marriage contract, subject to certain legal requirements and limitations. While marriage is intended to be a lifelong commitment, the state provides legal mechanisms for separation or divorce, which address the division of assets, custody of children, and other matters arising from the dissolution of the marriage. The process for obtaining a marriage license in Iowa involves meeting certain requirements, such as minimum age without parental consent, which is 18, and not being too closely related to the other party. Same-sex marriage is also legally recognized in Iowa following the Iowa Supreme Court ruling in Varnum v. Brien in 2009.