A godparent is chosen by the parents of a newborn Catholic. Under Canon Law 872-874, there are specific requirements to qualify as a godparent. Only one godparent is required, but two are allowed if they are of the opposite sex. If there is only one, a Christian witness might be asked. A Christian witness needs to be a baptized Christian.
The godparent needs to be a Catholic at least 16 years old who has had the sacraments of baptism, reconciliation, holy communion, and confirmation. They can’t be the baby’s mother or father. The godparents must not be bound by canonical penalty. They must have a desire to be a godparent and be willing to help teach the faith to the child if necessary. Regarding the first requirement that a godparent be Catholic, there is one exception. For a just cause, it is permitted to admit the Christian faithful of another Eastern non-Catholic Church to the function of a sponsor, but always at the same time with a Catholic sponsor.This means that a Ukrainian Catholic may have a Russian Orthodox godparent, provided that there is a good reason for it (family relationship) and he also has another Catholic godparent.
Godparents must attend the baptism to say their commitment. They should have a close and supportive relationship with the family. They need to be a good Christian. According to Christian Initation, General Introduction, the official praenotanda of the Rite of Christian Initiation, the following guidelines apply to godparents:
10. A godparent has to be approved by the judgment of the parish priest (pastor) being qualified to carry out the proper liturgical functions.
10.1. Each candidate may have either a godmother or a godfather or both a godmother and a godfather.
10.2. Those designated must have the capability and intention of carrying out the responsibility of a godparent and be mature enough to do so. A person 16 years of age is presumed to have the requisite maturity, but the diocesan bishop may have stipulated another age or the parish priest (pastor) or the minister may decide that there is a legitimate reason for allowing an exception.
10.3. Those designated as godparents must have received the three sacraments of initiation, baptism, confirmation, and eucharist, and be living a life consistent with faith and with the responsibility of a godparent.
10.4. Those desginated as godprents must also be members of the Catholic Church and be canonically free to carry out this office. At the request of parents, a baptized and believing Christian not belonging to the Catholic Church may act as a Christian witness along with a Catholic godparent.