First cousin marriages are not legal in Delaware. The state’s marriage laws explicitly prohibit marriage between first cousins, as well as other close relatives such as siblings, aunts, uncles, nieces, and nephews. This means you cannot legally marry your first cousin in Delaware.
Recent Legislative Efforts
In 2025, Delaware lawmakers considered a bill that would have changed the legal landscape for first cousin marriages. The proposed legislation aimed not to legalize first cousin marriages performed within Delaware, but rather to recognize such marriages if they were lawfully performed in another state or country.
For example, if a couple married as first cousins in a state where it is legal, Delaware would have recognized their marriage as valid for purposes such as immigration or legal benefits.
Outcome of the Bill
The bill was debated in the Delaware General Assembly but ultimately failed in the House on May 6, 2025, with a 23-12 vote against it. As a result, Delaware does not recognize first cousin marriages performed elsewhere, and it remains illegal to marry your first cousin in the state.
Practical Implications
You cannot marry your first cousin in Delaware.
Delaware does not recognize first cousin marriages performed out of state or abroad.
If you are married to your first cousin in a state or country where it is legal, Delaware will not treat your marriage as valid for state purposes, such as spousal benefits or immigration.
This law can create challenges for couples moving to Delaware or seeking to reunite families through immigration.
Table
| Situation | Legal in Delaware? |
|---|---|
| Marrying your first cousin in Delaware | No |
| Recognition of out-of-state cousin marriage | No |
Delaware law currently prohibits first cousin marriages and does not recognize such marriages performed elsewhere. Any efforts to change this law have so far been unsuccessful in the state legislature
Sources
[1] https://whyy.org/articles/first-cousin-marriages-delaware/
[2] https://en.wikipedia.org/wiki/Cousin_marriage_law_in_the_United_States
[3] https://legis.delaware.gov/BillDetail/141900
[4] https://legis.delaware.gov/BillDetail/141794
[5] https://www.delawarepublic.org/politics-government/2025-02-02/delaware-legislature-introduces-bill-to-recognize-lawful-first-cousin-marriages
