In Illinois, it is generally illegal to marry your first cousin, but there are two specific exceptions under state law:
- Both parties are 50 years of age or older, or
- Either party is permanently and irreversibly sterile, as certified by a licensed physician.
This means that, unless you meet one of these conditions, first cousin marriage is prohibited in Illinois. The law applies to both opposite-sex and same-sex couples, regardless of the reason for the marriage.
Additionally, Illinois does not recognize first cousin marriages performed out of state if the couple is domiciled in Illinois and does not meet the state’s exceptions.
Table
| Situation | Is First Cousin Marriage Legal in Illinois? |
|---|---|
| Both parties are 50+ years old | Yes |
| Either party is permanently and irreversibly sterile | Yes |
| Neither exception applies | No |
| Marriage performed out of state, couple lives in Illinois | No (unless above exceptions are met) |
You can only legally marry your first cousin in Illinois if you are both at least 50 years old or if one of you is permanently sterile, as documented by a physician. Otherwise, first cousin marriage is not permitted.
Sources
[1] https://en.wikipedia.org/wiki/Cousin_marriage_law_in_the_United_States
[2] https://www.illinoistimes.com/news-opinion/why-cant-cousins-marry-15982640
[3] https://www.reddit.com/r/immigration/comments/vupwva/i_am_an_american_citizen_and_live_in_illinois_i/
[4] https://www.ilga.gov/legislation/ilcs/documents/075000050K212.htm
[5] https://b100quadcities.com/first-cousin-marriage-chicago-illinois/
