Is Cousin Marriage Legal? Every US State and the UK Bill

Last updated: 13 November 2026. The state-by-state table was checked against each state’s marriage statute on official legislature websites or published code text (Justia and FindLaw where the official site could not be reached), including Connecticut Public Act 25-72 and Utah’s 2024 recodification. The UK section uses the Marriage Act 1949, bill records on bills.parliament.uk and government answers to written parliamentary questions. Genetic risk figures come from the Born in Bradford study published in The Lancet.

Short answer: In the United States it depends on the state. As of November 2026, 16 states and DC let first cousins marry, 7 allow it only under conditions such as age or infertility, and 27 prohibit it, most recently Connecticut from 1 October 2025. In England and Wales it is legal, but a bill to ban it is due a second reading on 15 January 2027.

Key takeaways

• 16 states plus DC allow first cousin marriage outright; Arizona, Illinois, Indiana, Maine, North Carolina, Utah and Wisconsin allow it with conditions; the other 27 states prohibit it. None of the statutes we checked bars second cousins.
• Recent changes all point one way: Tennessee banned first cousin marriage in 2024 and Connecticut in 2025, while a Florida ban failed in March 2026.
• A marriage valid where it took place is usually recognised elsewhere, but not always. Oklahoma and Washington expressly recognise out-of-state cousin marriages; Arizona expressly refuses to.
• In the UK, Richard Holden’s Marriage (Prohibited Degrees of Relationship) Bill fell without a debate in April 2026. A new bill from Dr Luke Evans is listed for second reading on 15 January 2027, and the government says it is “considering all options”.

Is cousin marriage legal in the United States?

There is no federal rule. Each state decides, and for first cousins (people who share a set of grandparents) the country splits roughly in half. Every state bans marriage between parents and children, siblings, and aunts or uncles and nieces or nephews. The disagreement starts one step further out.

Some states name “first cousins” directly. Others bar anyone “nearer of kin than second cousins”, which catches first cousins but leaves second cousins free to marry. Louisiana bars collateral relatives “within the fourth degree”, which includes first cousins, while Alaska bars only those closer than the fourth degree, so first cousins can marry there.

A marriage within a prohibited degree is usually void, meaning it never legally existed. Our guide to the difference between an annulment and a divorce explains how a court declares a void marriage a nullity, which can still matter for property and inheritance.

Which states allow first cousin marriage? Every state and DC

“Conditional” means the statute bans first cousin marriage in general but sets out an exception.

Which states let cousins marry only under conditions?

Five of the seven conditional states tie the exception to age or the ability to have children. The Arizona statute allows first cousins to marry if both are 65 or older, or if a superior court judge is given proof that one of them is unable to reproduce. Illinois needs both to be 50 or older, or a physician’s certificate filed with the county clerk that one party is “permanently and irreversibly sterile”. Indiana recognises the marriage only if both were at least 65. Utah allows it at 65, or at 55 with a district court finding that either party cannot reproduce; the rule moved from Utah Code 30-1-1 to 81-2-402 when Utah recodified its family law on 1 September 2024. Wisconsin allows it if the woman is 55 or older or a doctor’s affidavit states that either party is permanently sterile.

The other two are different. Maine lets first cousins marry if they provide a physician’s certificate of genetic counselling, with no age or fertility test. North Carolina allows first cousins to marry but not double first cousins, whose parents are two pairs of siblings.

Some “no” states have narrow carve-outs: Oregon allows cousins related only by adoption to marry, Nebraska’s ban covers first cousins “of the whole blood”, and Minnesota exempts marriages permitted by the established customs of aboriginal cultures.

What changed between 2024 and 2026?

• Tennessee (2024): the legislature amended Tenn. Code 36-3-101 to bar marriage with “the lineal descendant of a grandparent”, which covers first cousins. The bill became Public Chapter 806 in May 2024.
• Connecticut (2025): Public Act 25-72, signed on 23 June 2025, provides that “On and after October 1, 2025, no person may knowingly marry such person’s first cousin.” The Office of Legislative Research summary confirms the effective date. The act looks forward only, so earlier Connecticut marriages are not affected.
• Florida (2026): a ban bill died when the session ended in March 2026, and Governor Ron DeSantis urged lawmakers to try again in April. The 2026 Florida Statutes still bar only lineal relatives, siblings, aunts, uncles, nieces and nephews.

Will a cousin marriage from another state be recognised?

The general rule is that a marriage valid where it was celebrated is valid everywhere, but states can refuse recognition on public policy grounds, and some have written their answer into statute. Oklahoma bans cousin marriage but recognises a first cousin marriage “performed in another state authorizing such marriages”. Washington recognises marriages valid elsewhere unless they are bigamous or between siblings, children, grandchildren, aunts, uncles, nieces or nephews, so cousins qualify. Arizona goes the other way: ARS 25-112 accepts out-of-state marriages “except marriages that are void and prohibited by section 25-101”.

Couples who move to a state with a ban should take local advice. Couples married abroad may also need an apostille on their certificate before a US agency will accept it. Where you live can also decide whether you count as married under common law marriage rules. And although the Supreme Court has treated marriage as a fundamental right since Loving v. Virginia (1967), states still set the degrees of kinship within which people may not marry.

Is cousin marriage legal in the UK?

Yes. In England and Wales the relatives you cannot marry are listed in Schedule 1 to the Marriage Act 1949: parents, grandparents, children, grandchildren, siblings and half-siblings, a parent’s sibling, a sibling’s child, adoptive relationships and some step-relationships. Cousins are not on the list. The Ministry of Justice confirmed on 11 November 2024 that the prohibited degrees “include marriages to a sibling, parent or child, but not marriages between first cousins”, and that the Sexual Offences Act 2003 incest offences do not cover first cousins either. Scotland’s list, in the Marriage (Scotland) Act 1977, also stops at aunts, uncles, nieces and nephews.

Where is the UK bill to ban cousin marriage now?

Conservative MP Richard Holden introduced the Marriage (Prohibited Degrees of Relationship) Bill as a ten minute rule bill on 10 December 2024, “to prohibit the marriage of first cousins”. It never received a second reading and fell when the 2024-26 session ended on 29 April 2026.

Dr Luke Evans, Conservative MP for Hinckley and Bosworth, then won a place in the private members’ ballot and introduced the First Cousins (Prohibited Relationships) Bill on 17 June 2026. It would prohibit marriage, civil partnerships and sexual activity between first cousins. Its second reading is listed for 15 January 2027. Ballot bills get Friday debating time, but it would still need wide support or government help to become law.

The government has not taken a side. In written answers, ministers said on 14 July 2026 that a planned weddings law consultation “will focus on how people get married, rather than who is legally permitted to marry”. In September 2026 they said the government recognises “the serious concerns that have been raised”, “will be considering all options on how to tackle first cousin marriage”, and is looking at whether legislation or “education and community engagement are better options”. On 9 June 2026 a health minister said “the medical evidence is clear that first cousin marriages are high risk”.

Why do the rules exist?

The main reason given for modern bans is the higher chance of recessive genetic conditions in children whose parents are closely related. The leading UK evidence is the Born in Bradford cohort of 13,776 babies, published in The Lancet in 2013. In that study 18% of babies had first cousin parents, and consanguinity was linked to a doubling of the risk of a congenital anomaly (risk ratio 2.19) after adjusting for deprivation. The Department of Health and Social Care puts it as a rise from about 3% to about 6%, which also means most babies of cousin couples in the study had no anomaly. The authors recommended sensitive advice for couples at higher risk.

Supporters of bans also point to family pressure and forced marriage. Opponents say genetic counselling addresses the health risk without banning relationships between consenting adults, and that bans fall hardest on particular communities.

Several European countries have acted. Norway’s parliament voted on 12 June 2024 to ban first cousin marriage, with a power to grant consent for strong reasons, and to refuse recognition of foreign cousin marriages where a party was a Norwegian citizen or resident. The Swedish Riksdag approved a ban that took effect on 1 July 2026, and cousin marriages concluded abroad will generally not be recognised there. Denmark proposed a ban in December 2025, but the bill lapsed when an election was called in February 2026.

Frequently asked questions

Can second cousins marry in the United States?

Yes. None of the state statutes we checked bars second cousins. States that bar anyone “nearer of kin than second cousins”, such as Kentucky, Ohio and Washington, draw the line at first cousins.

Can you marry your first cousin in Texas?

No. The Texas licence application requires each applicant to state that the other is not the son or daughter of a parent’s brother or sister, and Penal Code 25.02 makes sex with a first cousin a third degree felony.

Which states allow first cousin marriage with no conditions?

Alabama, Alaska, California, Colorado, Florida, Georgia, Hawaii, Maryland, Massachusetts, New Jersey, New Mexico, New York, Rhode Island, South Carolina, Vermont and Virginia, plus the District of Columbia.

Is cousin marriage still legal in the UK in 2026?

Yes. First cousins can marry in England, Wales and Scotland. Holden’s ban bill fell in April 2026, and Dr Luke Evans’s bill is listed for second reading on 15 January 2027, so the law has not changed.

If we married legally in one state, are we married everywhere?

Usually, but not always. Oklahoma and Washington expressly recognise out-of-state cousin marriages, while Arizona refuses to recognise those that do not meet its age or fertility exceptions.

What is the genetic risk if first cousins have children?

The Born in Bradford study in The Lancet found that first cousin parents roughly doubled the risk of a congenital anomaly, which the UK health department describes as a rise from about 3% to about 6%. Genetic counselling can help couples understand their own risk.

This article is general information about cousin marriage laws in the United States and the United Kingdom as of 13 November 2026. It is not legal advice. Check the current statute and speak to a family lawyer about your own situation.