Is this true?

[Pompy]

Is it true that if one of the parties has not been baptized at the time of the marriage; the marriage is void.

 

[Fr.Charles_Grondin]

It depends on the circumstances.

If neither party to a marriage is Catholic then their exchange of consent is presumed to be valid.

If either party to a marriage is Catholic, then marriage of a baptized Catholic to an unbaptized person is invalid unless a dispensation is granted (canon 1086).

Even if someone was thought to have been baptized and later on it turns out that they were not, the marriage to a Catholic would be considered invalid (canon 1086 §3).

Can. 1086 §1. A marriage between two persons, one of whom has been baptized in the Catholic Church or received into it and has not defected from it by a formal act and the other of whom is not baptized, is invalid.

§2. A person is not to be dispensed from this impediment unless the conditions mentioned in cann. 1125 and 1126 have been fulfilled.

§3. If at the time the marriage was contracted one party was commonly held to have been baptized or the baptism was doubtful, the validity of the marriage must be presumed according to the norm of can. 1060 until it is proven with certainty that one party was baptized but the other was not.