Common Law Marriage in Missouri
Missouri does not recognize new common law marriages.
Not recognized
In Missouri, new common law marriages are not recognized.
No new common law marriage
Missouri does not create marriages by cohabitation. No matter how long a couple lives together or what they call each other, they are not married under Missouri law unless they go through a formal ceremony or obtain a valid marriage license. A valid common law marriage made in another state is still recognized here (see below).
Recognition from other states
Under the U.S. Constitution Full Faith and Credit Clause, every state — including Missouri — recognizes a valid common law marriage that was properly formed in another state. Moving across state lines does not undo a real marriage.
Source
Missouri does not recognize new common law marriages; it recognizes a valid out-of-state common law marriage under the Full Faith and Credit Clause (verified 2026-06)