The code of Catholic Church law issued in 1918 instructed pastors to see to that each person baptized was given a "Christian" name. If the parents of a child to be christened insisted on an "un-Christian" name, the baptizing priest was instructed to add a Christian name on his own initiative and to enter both names in the baptismal register.
The revised code of Church law (1983) is less restrictive. It simply forbids the giving of a baptismal name that is "alien to Christian sentiment." Most likely, however, this broader rule will not have much influence on the established custom of preferring the names of saints. This is good, for it is better for us to have a heavenly patron saint whom we can admire and turn to.
The New Testament records some name-changes, but there is no proof that they were assigned at baptism. Thus Jesus himself gave to Simon the Apostle the name Peter, and Saul the Pharisee from Tarsus became St. Paul. Not until the fifth century, however was there clear evidence of the giving of a name at baptism, and it was only in the 14th century that the Church began to insist on it. Not all the early Christian names were those of saints. In Mediterranean countries, many children were baptized under the name of Our Lord himself: "Jesus" (in Spain); "Emmanuel" (in Portugal); "Salvatore" (in Italy); "Christos" (in Greece). Sometimes, too, the names chosen were of Christian virtues: like Faith, Hope, Charity, Eusebia (i.e. Piety); or Christian aspirations, like Victor, Anastasia ("risen"), Renatus ("reborn"). Of the saints' names adopted, Scriptural names were particularly the favorites: Mary, Joseph, John the Baptist, Stephen, the apostles and evangelists.
In the centuries that followed, some names enjoyed temporary popularity according to the current devotion (or lack of devotion) of Catholic parents. Names given to boys were usually stronger and more sober. For example, in 13th century England, most of the men bore the names John, William, Robert, Richard or Henry.
That tendency continues today (of late the most popular name for boys has been Michael). Girls' names, on the other hand, have always been more fussy and lyrical. Some generations of parents have honored saints whose names later became less popular. Thus, in the first half of the 20th century, many baby girls were named after St. Rita of Cascia or St. Therese of Lisieux or St. Gemma Galgani. More recently, the names seem to have been suggested by secular celebrities, like Greta, Tammy or Jennifer; or fictional characters. Others have been simply invented.
To my mind, the strong old favorites are still best: John, Peter, David, Mary, Helen, Elizabeth, Catherine, etc. However, many other names are available for those who want something less routine. You can take the surnames of English martyrs: for instance, Reynolds (St. Philip Reynolds); Lloyd (St. John Lloyd); or even Jones (St. John Jones). It is also proper to use variants of saints' names: Shawn or Ian (St. John); Eric (St. Henry): Sheila or Cecily (St. Cecelia); Austin (St. Augustine); Consuelo or Mercedes (Our Lady); Jeffrey (St. Godfrey). Diminutives are permissible Linda (Rosalinda - St. Rose); Jilian (St. Julia); Jacqueline (St. James); Anita (St. Ann); Cindy (Lucinda - St. Lucy); Vicky (Victoria).
Some have said that you can find a saint to match any name. I don't think it's quite that easy. Family names wouldn't qualify, of course (e.g., Rutherford Birchard Hayes); and I have looked in vain for a St. Bruce, a St. Penelope ("Penny") or a St. Pamela ("Pam"). What is important, I think, is that the person baptized be given the name, not just of a saint but of a specific saint. Is Johnnie's patron St. John the Evangelist, St. John the Baptist, St. John Fisher, etc? Is Therese's St. Theresa of Avila, St. Therese of Lisieux or St. Therese Couderc, etc? When we know our saints, we can better use them as models and intercessors. That will make us appreciate better the meaning of the great doctrine of the "communion of saints" - the "family" spirit that unites those of us on earth with our brother and sister saints and namesakes in purgatory and in heaven.
--Father Robert F. McNamara