Those wishing to marry in the Catholic Church must be baptized, in good standing with the Church, must not have been married before with a few exceptions and must be marrying someone of the opposite sex. These are some of the requirements to have a sacramental marriage as opposed to just a natural marriage. The Catholic Church requires special preparations before giving a couple the sacrament of marriage.
While both partners need not be Catholic, they both need to have been baptized as Christian. If one partner has not been baptized, special permission is required by the local bishop. The same is true if one of the partners is not Christian.
To be in good standing in the Catholic Church, one must attend church regularly and must be free from scandal. This sometimes includes couples living together before marriage.
If someone was married before, his marriage must have ended with the death of his spouse or with an annulment of the marriage through the Catholic Church before he is able to remarry. The Catholic Church only marries those of opposite genders.
Formal marriage preparations required by the Church include marriage preparation classes, reception of the Sacrament of Reconciliation, information about natural family planning and sometimes even a weekend retreat.