Three of the Corleone children have very ethnic-sounding names...

Santino
Frederico
Constanzia

But then there's Michael. It's odd seems odd that one child would have an "American" name. Is it possible the name given to him at birth was Michele, the Italian equivalent? Any opinions?

I believe that Michael's birth name was originally "Michele" because it was pronounced that way when Appolonia's father introduced him to her family. Michael is used by all his Italian-American fiends and family. Kinda like how all the children have their own "American version" of their name (Sonny, Fredo, Connie). I'm not positive, but I have a feeling that Michael did in fact have a different birth name.

Maybe Puzo deliberatley gave Michael an American-sounding name to further show his initial alienation from the family and initial refusal to be part of it?

I think so, too. It's another little subtle touch--like (in the film) having Barzini smoke a cigarette while all the "moustache Petes" were smoking DiNobile's.

Also italians especially at that time were very religious oriented, even the Mafia, as the movie highlights. As many woman are named Mary or Marie in Italy and Spain, after the virgin Mary, so are many males named Joesph or Joe or Michael after the arch-angel.

Micheal's name was really Micheal. I remember seeing on the family tree on the DVD-there is Santino, Fredesco, Constanzia, and Micheal. They were obviously going by all of the birth names here so Micheal must be the birth name.

I rember thinkin that was strange, but he was like the odd one out since birth