In Delaware, it is illegal to marry your first cousin under current state law. The Delaware Code explicitly prohibits marriages between close relatives, including first cousins, rendering such unions void within the state. This prohibition reflects Delaware’s longstanding legal stance on close-kin marriages, aiming to prevent the potential genetic and social concerns commonly cited with marriages between close family members.
In early 2025, Delaware lawmakers considered legislation that would have changed part of the law by recognizing lawful first cousin marriages performed outside of Delaware. This bill, sponsored by State Representative Madinah Wilson-Anton, sought to allow couples who legally married as first cousins in other jurisdictions to have their marriages recognized for legal purposes in Delaware, such as immigration and spousal benefits. However, this proposed change did not legalize the performance of new first cousin marriages within Delaware itself — the state’s prohibition remained intact. The bill received considerable attention for its social and cultural implications, especially reflecting the diversity within the community, but it ultimately failed in the state House of Representatives in May 2025 by a decisive vote of 23 to 12.
The push for recognition of out-of-state cousin marriages was partly triggered by real-life challenges faced by Delaware residents whose legal first cousin marriages were not recognized by the state, causing immigration and legal complications. For example, federal authorities denied immigration petitions for spouses who were first cousins because Delaware law did not recognize their marriage, effectively forcing families to relocate to states where such marriages are permitted.
Currently, Delaware remains among the 25 states in the U.S. that ban marriages between first cousins. The prohibition is clear and included in the Delaware legal code. This contrasts with about 18 other states where first cousin marriages are legal either outright or with specific caveats, such as requirements for genetic counseling. Some states in neighboring regions recognize cousin marriages, but Delaware maintains its traditional ban, reflecting cultural and legal caution toward such unions.
Despite the bills and debates, Delaware has not softened its stance on cousin marriage, and any marriage between first cousins entered into in Delaware is invalid and voidable under law, with no legal recognition or protections afforded. The topic remains socially sensitive and legislatively divisive, but as of mid-2025, the law is firm that marrying your cousin in Delaware is illegal and not recognized by the state.
Sources
(https://www.delawarepublic.org/politics-government/2025-02-02/delaware-legislature-introduces-bill-to-recognize-lawful-first-cousin-marriages)
(https://legiscan.com/DE/bill/HB8/2025)
(https://whyy.org/articles/first-cousin-marriages-delaware/)
(https://www.delawarepublic.org/politics-government/2025-05-08/bill-to-recognize-lawful-first-cousin-marriages-in-delaware-fails-in-state-house)
(https://delcode.delaware.gov/title13/c001/sc01/index.html)
