Can First Cousins Marry In Washington? (Explained)

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

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 Evergreen 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 Washington Marriage Laws Say About First Cousins?

The Washington marriage laws set out a list of prohibited relationships. Here is the relevant excerpt:

Marriages in the following cases are prohibited:

When the spouses are nearer of kin to each other than second cousins, whether of the whole or half blood computing by the rules of the civil law.

Washington marriage laws

Clearly, second cousins are allowed to marry. That is the threshold. But what does “whole or half blood” mean?

And what are other cousin relationships that are closer than second? Let’s take a closer look.

First cousins are not allowed

First cousins are closer (nearer of kin) than second cousins.

This wording ensures that first-cousin marriages are not allowed in the state.

Whole or half blood

“Half blood” is a rather archaic term now, but there is a simple explanation.

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

Their children are first cousins of the whole blood.

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

Their children are first cousins of the half blood. We also call them half first cousins. This relationship is not allowed to marry under the Washington laws.

Basically, if your cousin’s parent is a half sibling of your parent, then you are half first cousins.

What about first cousins once removed?

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

This is a closer relationship than second cousin, which means it is not a valid marriage in Washington.

If you need a more detailed explanation, check out our in-depth article on first cousins once removed.

Are there any exceptions to the laws?

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

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

Marrying in Washington

Types Of Cousins That Can Get Married In Washington

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 Washington Marriage Application Form Ask If You’re Related?

Some U.S. states have a section in their marriage application forms where the couple must state whether they have a blood relationship.

You can see an example in our article on whether first cousins can marry in Texas.

We reviewed the application form for a marriage license from King County in 2022. There is no such question present.

I point this out because I can see how people could get married without being aware of the impediment. However, when you sign the form you are affirming that there is no impediment to your marriage.

Do Nearby States Allow First Cousins To Marry?

Washington is bordered by Idaho and Oregon. Neither of these neighboring states allow first cousins to marry.

The nearest alternative is probably the northern end of the Golden State. Check out our article on first cousins marrying in California.

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 Washington as a destination wedding spot?

Consider going to California as an alternative option. There are many fabulous wedding venues on offer.

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 on what second cousins are.

Frequently Asked Questions

Here are some quick answers to common questions.

Does Washington allow relatives to marry?

Washington 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 Washington?

Washington 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 Washington?

Marriage between second cousins is legal in Washington.


The codes and laws referenced in this article may not be the most recent version. Washington 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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