Ohio prohibits marriages between first cousins, one of many states that bans such unions. Here’s an overview of Ohio’s law and how it compares nationally.

First Cousin Marriage is Banned

Under Section 3101.01 of the Ohio Revised Code, marriages between first cousins are prohibited in the state. This ban encompasses biological cousins, adopted cousins, and double first cousins.

Any Ohio cousins who attempt to wed or have a sexual relationship can face felony incest charges punishable by up to 5 years in prison. The law clearly defines first cousins as within the degrees of consanguinity prohibiting marriage.

No Exceptions to the Ban

Unlike some states, Ohio makes no exceptions to allow first cousin marriage under special circumstances. It does not matter if you are an older couple past childbearing age, cannot have children, or undergo genetic testing.

The prohibition is effectively absolute. First cousins in Ohio cannot legally get married under any conditions.

Differing Laws Among States

It’s important to understand that cousin marriage laws vary substantially across the 50 states. About half of U.S. states currently allow first cousin marriage with no restrictions or limitations.

However, many other states join Ohio in imposing an outright ban, including neighboring states like Indiana, Kentucky, and West Virginia. Cousins face a patchwork of changing laws nationwide.

Social Stigma Also Plays a Role

Along with legal prohibitions in Ohio, social disapproval toward cousin marriage persists. Even if allowed, cousins might face backlash and rejection from family and friends for bucking marital norms.

Opponents argue cousin marriages risk birth defects and developmental problems in potential offspring. But proponents believe the small risks can be mitigated and should not prohibit personal choice.

Rationale Behind Cousin Marriage Bans

Supporters of cousin marriage prohibitions say they are justified to prevent risks of congenital disabilities and infant mortality. Critics argue banning consensual relationships between adults is an overreach.

Ohio lands solidly on the side of prohibition to preclude any genetic risks. But the American laws contrast with many other nations where cousin marriage is common.


In Ohio, those who wish to enter marriages with first cousins face not only social hurdles but firm legal barriers. No exceptions exist to allow cousin couples to wed. Traveling to a different state may provide marriage opportunities not available in Ohio itself. But within its borders, cousin unions will remain unlawful barring changes to the current statute.