No, marrying a first cousin is illegal in Oregon. The state’s marriage laws strictly prohibit such unions, making them void if performed within the state. This rule stems from longstanding statutes aimed at preventing incestuous relationships.
Legal Basis
Oregon Revised Statutes (ORS) 106.020 explicitly lists prohibited marriages. Subsection (2) states that marriages are void when parties are “first cousins or any nearer of kin to each other, whether of the whole or half blood, whether by blood or adoption, computing by the rules of the civil law.”
A sole exception applies to first cousins by adoption only, where the marriage remains valid. This law, last amended in 2015 with no changes noted through 2026, ensures county clerks deny licenses to first cousins.
Implications of Violation
Any first-cousin marriage solemnized in Oregon is “absolutely void,” lacking legal recognition. Couples cannot obtain a license beforehand, as clerks verify prohibited relationships.
Out-of-state marriages may not hold up in Oregon courts for inheritance or divorce purposes. Relatedly, ORS 106.140 penalizes officiants who perform unlawful ceremonies.
Broader Context
Only about half of U.S. states ban first-cousin marriages outright; Oregon aligns with stricter jurisdictions like Texas and Nevada. Genetic risks, such as higher chances of birth defects in offspring (around 4-7% vs. 3% baseline), underpin these laws, though modern counseling mitigates concerns in permissive states.
Domestic partnerships follow identical prohibitions under ORS 106.305. Second cousins and beyond face no restrictions.
Historical Notes
Oregon’s consanguinity rules trace to civil law traditions, defining kinship degrees precisely. Courts have upheld the ban, occasionally critiquing it as outdated but deferring to legislature.
No recent bills (as of January 2026) propose reform, despite national debates on personal freedoms. Couples often relocate to states like California, where it’s legal.
SOURCES
- https://www.reddit.com/r/legaladvice/comments/3bjwyd/is_it_legal_to_have_sexual_relations_with_a_cousin/
- https://dataminingdna.com/can-first-cousins-marry-in-oregon/
- https://theamm.org/marriage-laws/oregon/170
