SALT LAKE CITY — While it may come as a surprise, Utah permits marriage between first cousins — but only under specific circumstances. The state, known as the Beehive State, is among a handful of U.S. states where cousin marriage is legal with certain restrictions in place.
According to the Utah State Courts, first cousins can legally marry if both individuals are at least 65 years old. Alternatively, cousins aged 55 and older may marry if they can prove they are unable to have children. Outside of these exceptions, marriages between close relatives, including cousins under the threshold age, are considered “incestuous and void” under state law.
The court also clarifies that marriage is strictly prohibited between closer family relations such as siblings, parents and children, aunts, uncles, nieces, and nephews.
Utah joins seven other states — including Arizona, Illinois, Indiana, Maine, Minnesota, and Wisconsin — that permit some forms of first cousin marriage, often tied to factors like age or infertility. Meanwhile, other states either fully ban cousin marriage or allow it without significant restrictions.
Polygamy and Bigamy: What’s Legal in Utah?
Despite the long-standing association between Utah and polygamy, the practice is illegal in the state. Utah’s constitution specifically bans polygamous and plural marriages.
Under Utah law, individuals who attempt to marry while still legally married to another person can be charged with bigamy. Bigamy is treated seriously and can result in second- or third-degree felony charges, depending on the circumstances.
Marrying a Minor: Rules and Recent Changes
In Utah, minors as young as 16 can legally marry, but only under strict conditions. Those aged 16 or 17 must have written permission from a parent or legal guardian, and the consent must be submitted in person to the county clerk’s office.
Additionally, the minor must seek approval from a juvenile court. The court will only authorize the marriage if it determines that the union is voluntary and in the minor’s best interests.
Recent legislative changes have tightened the rules further. During the 2025 session, Senator Jen Plumb sponsored a bill that narrowed the allowed age difference between a minor and an adult spouse from seven years down to four years. The law also introduced a mandatory 72-hour waiting period after a petition for marriage authorization is filed, giving minors and their guardians more time to reconsider before proceeding.
When Is a Marriage Considered Void in Utah?
Certain marriage situations are automatically considered invalid under Utah law.
If one of the parties is already legally married to someone else, any new marriage is deemed void. Similarly, if a minor attempts to marry without the required court approval, that marriage is invalid.
Moreover, if an individual is in the midst of divorce proceedings and their divorce has not yet been finalized by the court, any attempt to remarry during that period would result in a void marriage.
