How Old Do You Have to Be to Get Married?

Marriage age laws are not a static feature of the legal landscape. The United States has seen a significant wave of legislative reform since 2016, with state after state raising the minimum marriage age to 18 with no exceptions. The movement is driven by documented evidence of harm from child marriage, including higher school dropout rates, higher rates of domestic violence, and long-term economic disadvantage for those married as minors.

The legal landscape in 2026 is dramatically different from 2015. In 2015, most US states allowed marriage at 16 or younger with parental consent, and some had no explicit minimum age at all (relying on a common law tradition that allowed marriage at 12 for girls and 14 for boys). Today, over 38 states have an absolute 18 minimum. The remaining states are under active legislative pressure.

Understanding these laws matters for a few groups: young adults approaching marriage age who want to know their rights, parents and guardians who may face pressure from cultural or family traditions, and advocates and researchers tracking the policy landscape.

For most of American history, marriage age rules derived from English common law, which set 12 for girls and 14 for boys as the minimum age (based on medieval concepts of puberty). These ages were not based on emotional or developmental readiness; they were rooted in property and inheritance law of the feudal era.

US states began codifying their own marriage age statutes in the 19th and early 20th centuries, with wildly inconsistent results. By the mid-20th century, most states had set some minimum age but nearly all allowed exceptions for parental consent or judicial approval. Federal immigration law in the late 1800s began to treat child marriage as a concern in some contexts, but marriage law itself remained entirely state-level.

The modern reform movement gained momentum after the 2016 publication of research documenting the scale of child marriage in the US. A 2021 study found that approximately 300,000 children were married in the US between 2000 and 2018, predominantly girls. This data, combined with international attention from the UNICEF push to end child marriage globally, galvanized state legislative action.

Most developed countries have set 18 as the national minimum marriage age with very narrow court-ordered exceptions. Germany (18), France (18), Australia (18 nationally, with some narrow state court exceptions), Canada (18 in most provinces, 16 in some), and the UK (18 since 2022) all have stronger national protections than the US, which still relies on state-by-state legislation.

The UNICEF standard defines child marriage as any marriage where either party is under 18. By this definition, the US still legally permits child marriage in a minority of states, putting it in a category with countries that have weaker protections by international standards.

Countries that have successfully eliminated child marriage entirely include Australia (federal ban 2017), Ireland, the Netherlands, and Nordic countries. Their approach combined legislative action with social support systems for young women and girls.