Can First Cousins Marry In South Dakota? (Explained)

It is currently illegal for first cousins to marry in South Dakota.

First cousins once removed and other more distant relationships are allowed.

However, half first cousins (children of half siblings) are also not permitted to marry.

This article reviews the important aspects of cousin marriage within the Mount Rushmore State.

What Do The South Dakota Marriage Laws Say About First Cousins?

The South Dakota marriage laws have a fairly lengthy list of relationships. We’ve broken up the text and highlighted the relevant parts below:

Marriages between parents and children, ancestors and descendants of every degree, and between brothers and sisters of the half as well as the whole blood, and between uncles and nieces, or aunts and nephews,

and between cousins of the half as well as of the whole blood,

are null and void from the beginning, whether the relationship is legitimate or illegitimate. The relationships provided for in this section include such relationships that arise through adoption

South Dakota marriage laws

Basically, first cousins and half first cousins (we’ll explain that next) are not permitted to marry. This is regardless of whether the relationship is through adoption.

What does “of the half as well as of the whole blood” mean?

Let’s quickly explain the bit about “half” and “whole blood”. When two siblings share the same parents, they are whole blood relatives i.e. “full siblings”.

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

The children of full siblings are first cousins. The children of half siblings are half first cousins.

If that seems confusing, then you can see a diagram in our companion article that describes what a half cousin is.

The South Dakota laws are one of the few that explicitly prohibit half first cousins.

Has the ban always been in place?

South Dakota introduced their ban on first cousin marriages in the 1860s.

Are there any exceptions to the laws?

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

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

Marrying in South Dakota

Types Of Cousins That Can Get Married In South Dakota

Relationships that are further out than first cousins are allowed.

This means that first cousins once removed can marry in the state.

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 South Dakota 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 North Dakota.

We reviewed the application form for a marriage license from the Department Of Health in South Dakota 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?

South Dakota is bordered by Iowa, Minnesota, Montana, Nebraska, North Dakota, and Wyoming. None of these six states allow first cousins to marry.

The nearest option is probably the Centennial State. Check out our article on first cousins marrying in Colorado.

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 North Dakota as a destination wedding spot?

You could consider Colorado as an alternative destination! There are many beautiful venues in the state.

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 what second cousins are. The infographics should show how it works.

Frequently Asked Questions

Here are some quick answers to common questions.

Does South Dakota allow relatives to marry?

South Dakota 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 South Dakota?

South Dakota 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 South Dakota?

Marriage between second cousins is legal in South Dakota.


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

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.