As of May 2025, it is illegal to marry your first cousin in Delaware. The state is among those that prohibit marriages between first cousins, and this restriction applies to marriages performed within Delaware’s borders.
Out-of-State and Foreign Marriages
There was a recent effort in the Delaware legislature to change how the state treats first cousin marriages performed elsewhere.
House Bill 8 and its substitute aimed to recognize first cousin marriages that were legally performed in other states or countries—even though such marriages cannot be performed in Delaware itself.
However, this bill failed to pass in May 2025. As a result, Delaware does not recognize first cousin marriages performed outside the state.
What This Means for Residents
- You cannot legally marry your first cousin in Delaware.
- If you marry your first cousin in a state or country where it is legal, Delaware does not recognize that marriage as valid.
- Delaware’s law is stricter than some other states, which may recognize out-of-state cousin marriages even if they do not allow them to be performed locally.
Summary Table
| Scenario | Legal in Delaware? |
|---|---|
| Marrying your first cousin in Delaware | No |
| Living in Delaware after marrying your cousin elsewhere | No recognition |
| Marrying a more distant cousin (e.g., second cousin) | Not explicitly addressed |
It is illegal to marry your first cousin in Delaware, and the state does not recognize first cousin marriages performed elsewhere. Recent legislative attempts to change this failed, so the law remains unchanged in 2025.
Sources:
- https://legis.delaware.gov/BillDetail/141794
- https://en.wikipedia.org/wiki/Cousin_marriage_law_in_the_United_States
- https://legis.delaware.gov/BillDetail/141900
- https://www.billtrack50.com/billdetail/1786615