What are the stipulations for a mixed marriage to be valid in the Catholic Church?

Catechism of the Catholic Church: Mixed marriages and disparity of cult

1633 In many countries the situation of a mixed marriage (marriage between a Catholic and a baptized non-Catholic) often arises. It requires particular attention on the part of couples and their pastors. A case of marriage with disparity of cult (between a Catholic and a non-baptized person) requires even greater circumspection.

1634 Difference of confession between the spouses does not constitute an insurmountable obstacle for marriage, when they succeed in placing in common what they have received from their respective communities, and learn from each other the way in which each lives in fidelity to Christ. But the difficulties of mixed marriages must not be underestimated. They arise from the fact that the separation of Christians has not yet been overcome. The spouses risk experiencing the tragedy of Christian disunity even in the heart of their own home. Disparity of cult can further aggravate these difficulties. Differences about faith and the very notion of marriage, but also different religious mentalities, can become sources of tension in marriage, especially as regards the education of children. The temptation to religious indifference can then arise.

1635 According to the law in force in the Latin Church, a mixed marriage needs for liceity the express permission of ecclesiastical authority [Cf. CIC, can. 1124]. In case of disparity of cult an express dispensation from this impediment is required for the validity of the marriage [Cf. CIC, can. 1086.]. This permission or dispensation presupposes that both parties know and do not exclude the essential ends and properties of marriage; and furthermore that the Catholic party confirms the obligations, which have been made known to the non-Catholic party, of preserving his or her own faith and ensuring the baptism and education of the children in the Catholic Church [Cf. CIC, can. 1125.].

1636 Through ecumenical dialogue Christian communities in many regions have been able to put into effect a common pastoral practice for mixed marriages. Its task is to help such couples live out their particular situation in the light of faith, overcome the tensions between the couple's obligations to each other and towards their ecclesial communities, and encourage the flowering of what is common to them in faith and respect for what separates them.

1637 In marriages with disparity of cult the Catholic spouse has a particular task: "For the unbelieving husband is consecrated through his wife, and the unbelieving wife is consecrated through her husband." [1 Cor 7:14.]. It is a great joy for the Christian spouse and for the Church if this "consecration" should lead to the free conversion of the other spouse to the Christian faith. [Cf. 1 Cor 7:16]. Sincere married love, the humble and patient practice of the family virtues, and perseverance in prayer can prepare the non-believing spouse to accept the grace of conversion.

Please see also:

Mixed Marriages Marriages between a catholic and a baptized Christian who is not in full communion with the Catholic Church are called mixed marriages. For mixed marriages, permission (not dispensation) from the local ordinary (usually the bishop) is required for validity. Marriages between Catholics and unbaptized persons (disparity of cult) are invalid unless a dispensation from the local ordinary is granted. All this presupposes that these marriages are celebrated with all other necessary conditions fulfilled. The local bishop may grant permission or dispensation for such marriages on the following conditions:

• The Catholic party declares that he or she is prepared to remove dangers of falling away from the faith and makes a sincere promise to do all in his power to have all the children baptized and brought up in the Catholic Church.
• The other party is to be informed at an appropriate time of these promises that the catholic person has to make. It is important that the other person be truly aware of the commitments and obligations of the Catholic spouse.
• Both persons are to be instructed with respect to the essential ends and properties of marriage, which are not to be excluded by either party.
• The man and woman should marry in the Catholic Church. The canonical from (Church ceremony with an authorized catholic priest or deacon and at least two other witnesses present) is to be followed. When there are serious difficulties, the local bishop may give a dispensation and allow another form which is public (such as a civil ceremony) to be followed. It is never allowed, however, to have a Catholic priest or deacon and a non-Catholic minister, rabbi, or public official, each performing his or her own rite, asking for the consent of the parties. Likewise, it is forbidden to have another religious marriage ceremony before or after the Catholic ceremony for giving or receiving the matrimonial consent. Marriage consent is given only once.

cf. [Handbook of Prayers | Rev. James Socias, Publisher]

Marriage of a catholic and a non catholic baptised is prohibited, without extra permission according to cann. 1124 and 1125 CIC (Caution: links to old version of CIC, Pope Benedict XVI changed can. 1124 in 2009)

Can. 1124 Without express permission of the competent authority, a marriage is prohibited between two baptized persons of whom one is baptized in the Catholic Church or received into it after baptism and the other of whom is enrolled in a Church or ecclesial community not in full communion with the Catholic Church.

Can. 1125 The local ordinary can grant a permission of this kind if there is a just and reasonable cause. He is not to grant it unless the following conditions have been fulfilled:

1/ the Catholic party is to declare that he or she is prepared to remove dangers of defecting from the faith and is to make a sincere promise to do all in his or her power so that all offspring are baptized and brought up in the Catholic Church;

2/ the other party is to be informed at an appropriate time about the promises which the Catholic party is to make, in such a way that it is certain that he or she is truly aware of the promise and obligation of the Catholic party;

3/ both parties are to be instructed about the purposes and essential properties of marriage which neither of the contracting parties is to exclude.

If this permission is granted, they can get married in the "canonical form" (the normal catholic wedding liturgy). If they want to marry in another form, they need a dispens according to can. 1127 § 2. Marrying without the permission but in canonical form would be prohibited, but valid. Marrying without canonical form and dispens would be invalid.

Can. 1127 §2. If grave difficulties hinder the observance of canonical form, the local ordinary of the Catholic party has the right of dispensing from the form in individual cases, after having consulted the ordinary of the place in which the marriage is celebrated and with some public form of celebration for validity. It is for the conference of bishops to establish norms by which the aforementioned dispensation is to be granted in a uniform manner.

This sounds very complicated, but it is not necessarily so. In Germany both the permission and the dispense is a routine act organised by your pastor, but other countries may have different customs and norms of the conference of bishops. Ask your local pastor for information special to your diocese.

The baptism of the children is unrelated to the marriage status of the parents.

the woman is a devout Catholic and the man is a Baptist, ... would like to be married in a non-catholic church. Would the Catholic Church consider such a marriage valid?

Canon law 1108 §1 clearly states that such marriages will not be valid.

I have heard that a special dispensation from the local bishop is necessary. How should that be acquired?

Such dispensations are given only on certain conditions. Please see Geremia's answer for those conditions. Procedure to acquire such dispensation may differs for each diocese. You should contact your local parish priest. He will guide you on how to proceed.

Please note that such dispensations are given only for marriages done in the Catholic Church. There is no provision to grant such dispensation for a non-catholic marriages (i.e marriage done out side the church).

If the marriage is valid, is it also allowed to baptize the children Catholic?

Baptizing an infant has nothing to do with its parents marital status. If the priest has a reasonable hope that the child will be brought up in a good Catholic environment, the child can be baptized even if its parents are not in good standing with the church.

According to the 1983 Code of Canon Law, mixed marriages (where one party is non-Catholic) require permission from the "local ordinary" or bishop (Can. 1124). The children must be baptized and raised Catholic, and the non-Catholic has to be okay with this (Can. 1125). They must have a Catholic wedding and cannot "have another religious celebration of the same marriage to give or renew matrimonial consent before or after the" Catholic wedding (Can. 1127 §3).

If a mixed marriage of doubtful validity already exists, you need to talk to a Catholic priest about convalidation or radical sanation.