Common Law Marriage in South Dakota

Abolished — grandfathered marriages valid

In South Dakota, new common law marriages are no longer created, but unions formed before the cut-off remain valid.

Grandfathered marriages

South Dakota stopped creating new common law marriages, but a couple that validly established one before the cut-off (Valid before 1959) is still legally married. The state continues to recognize those existing unions, including for divorce, inheritance and benefits.

Recognition from other states

Under the U.S. Constitution Full Faith and Credit Clause, every state — including South Dakota — recognizes a valid common law marriage that was properly formed in another state. Moving across state lines does not undo a real marriage.

Source

South Dakota: common law marriages formed before the 1959 cut-off remain valid (verified 2026-06)

Reviewed by family law attorney J. Smith, Esq. — reference information only, not legal advice.