Can First Cousins Marry In Montana? (Explained)

It is currently illegal for first cousins to marry in Montana.

First cousins once removed are also not allowed to marry. The state also does not allow marriage between half first cousins.

Second cousins and other more distant relationships are allowed.

This article reviews the important aspects of cousin marriage within the Silver State. If you’re not familiar with half first cousins (or even first cousins once removed), we’ll explain them in full.

What Do The Montana Marriage Laws Say About First Cousins?

The Montana marriage laws include a brief list of prohibited relationships.

Here is the relevant section:a marriage between an ancestor and a descendant or between a brother and a sister, whether the relationship is by the half or the whole blood, or between first cousins;

Montana marriage laws

Clearly, first cousins aren’t allowed to marry under the Montana laws. But what about other relationships?

What about first cousins once removed?

The child of your first cousin is your first cousin once removed.

This relationship isn’t mentioned in these laws, unlike in some other states.

As it is more distant, it doesn’t prohibit marriage. If you need a more detailed explanation of the family structure, check out our in-depth article on first cousins once removed.

Half first cousins

You’ll notice that “half or the whole blood” is mentioned in relation to brothers and sisters.

These blood terms are rather archaic now. Let’s break it down.

When two siblings share the same parents, they are whole blood relatives. We usually call them full siblings.

When the siblings only share one parent, we call them half-siblings. This is also known as a half blood relationship.

If your cousin’s parent is a half sibling of your parent, then you are half first cousins. But half first cousins aren’t mentioned in the laws.

Are there any exceptions to the laws?

Some other states generally don’t allow first cousin marriage but have some allowances based on child-bearing capacity or other criteria.

In contrast, Montana has a blanket ban within the state. There are no special exceptions.

Marrying in Montana

Other Types Of Cousins That Can Get Married In Montana

Marriages between second cousins are allowed. Of course, more distant cousins are also permitted.

If you’re not sure what the difference is between the various relationships, the links below will give you diagrams and clear explanations.

Does The Montana Marriage Application Form Ask If You’re Related?

We reviewed the application form for a marriage license in Montana in 2022.

The form has a section that asks if the applications are related. If so, the nature of the relationship must be stated.

If you are second cousins or another type of non-prohibited relationship, you must still disclose this to the clerk.

Don’t worry, this is not an impediment to securing the marriage license.

Do Nearby States Allow First Cousins To Marry?

Montana is bordered by Idaho, North Dakota, South Dakota, and Wyoming. None of these neighboring states allow first cousins to marry.

The nearest options are further south. Check out these two articles:

Looking for a destination wedding spot?

Do you live in a state or country where first cousin marriage is legal and you simply wanted to visit Montana as a destination wedding spot?

Consider these other states as alternative options! They both have beautiful wedding venues.

Looking to relocate?

Some first cousins choose to relocate permanently to a state where their marriage will be legal.

Review your options and future plans carefully. You may wish to sit down with an attorney to consider all the implications.

Some states in the U.S. will not recognize legal marriages from other states.

Roman Catholic Marriages

Even if close cousins move to another state that allows their civil marriage, they will face separate hurdles if they want a wedding in a Roman Catholic church.

Historically, the Catholic Church hasn’t encouraged first cousin marriages. However, the church laws have been relaxed somewhat in recent years.

There is a process that first cousins need to go through with the hierarchy in order to get permission to marry in a church ceremony. This is known as a dispensation.

You can read a more detailed explanation here on how first cousins can have a Catholic wedding.

What about other cousins?

Second cousins (and further out) don’t need to get special permission for a Catholic Church marriage.

We suggest that you mention to your priest that you are second cousins before the service. This means he won’t get uneasy if he hears mention of “cousins” from other people.

If you’re not sure about whether you are first or second cousins, check out our article that explains second cousin relationships.

Frequently Asked Questions

Here are some quick answers to common questions.

Does Montana allow relatives to marry?

Montana does not allow close relatives to marry.

More distant relatives such as second cousins are allowed to marry in the state.

Can you marry a sibling in Montana?

Montana does not allow siblings to marry. Half-siblings are also not allowed to marry in the state.

Is it legal to marry your second cousin in Montana?

Marriage between second cousins is legal in Montana.


The codes and laws referenced in this article may not be the most recent version. Montana may have more current or accurate information.

We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on other sites. Please check official sources.

Margaret created a family tree on a genealogy website in 2012. She purchased her first DNA kit in 2017. She created this website to share insights and how-to guides on DNA, genealogy, and family research.

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