First cousin marriage in Wisconsin is generally prohibited by law. According to Wisconsin Statutes section 765.03, “no marriage shall be contracted…between persons who are nearer of kin than second cousins,” which includes first cousins. There is, however, a narrow exception: if the female in the couple is at least 55 years old, or either party can present a physician’s affidavit stating permanent sterility, then the marriage is permitted under state law.
This means that unless one of these exceptions is satisfied—either the woman is of sufficient age or one partner is sterile—first cousins are not allowed to legally marry in Wisconsin. The restrictions are rooted in historical concerns about genetic disorders, though contemporary science shows the risks are often lower than previously assumed. Nevertheless, Wisconsin maintains these specific restrictions in its marriage statutes.
First cousin marriages that do not meet the exceptions are considered void in Wisconsin. Out-of-state marriages present another layer of complexity. Some couples travel to states where cousin marriage is legal to marry and then return to Wisconsin. However, Wisconsin law explicitly recognizes that such marriages are void if they were entered into by residents for the purpose of evading state law. In other words, Wisconsin will not validate a first cousin marriage conducted elsewhere if it would have been illegal had it taken place in Wisconsin.
Second cousin marriage, by contrast, is fully legal in Wisconsin because the law only bans marriages between persons who are “nearer of kin than second cousins”. The state does not restrict marriage between more distant relatives, such as second cousins or cousins further removed.
If a marriage between first cousins is discovered to have occurred without meeting the outlined exceptions, it may be annulled or declared invalid by a court. Attempts to skirt the law by marrying out of state and reestablishing residency in Wisconsin are unlikely to succeed, as the state has specific measures in place to prevent such circumvention.
First cousins cannot marry in Wisconsin unless the female is at least 55 or one party is sterile and certified as such by a physician. Marriages that occur without meeting these exceptions are void, and out-of-state cousin marriages are not recognized if made to avoid Wisconsin law. Second cousin marriage is legal with no restrictions. These provisions are detailed in both the state statutes and reinforced by judicial interpretation.
Sources
[1] https://en.wikipedia.org/wiki/Cousin_marriage_law_in_the_United_States
[2] https://docs.legis.wisconsin.gov/document/statutes/765.03
[3] https://en.wikipedia.org/wiki/Cousin_marriage
[4] https://docs.legis.wisconsin.gov/statutes/statutes/765/03?view=section
[5] https://myattorneyusa.com/immigration-blog/immigration-to-the-usa/marriage-invalid-if-it-goes-against-public-policy-of-state-of-residence-matter-of-zappia/
