| Name | M/F | Meaning |
|---|---|---|
| Oar | ![]() |
Meaning : Used in : Portuguese |
| Odysseus | ![]() |
Meaning : Angry Man Used in : Australian, German, Greek, Portuguese |
| Olavo | ![]() |
Meaning : Heir, Ancestor Used in : Portuguese |
| Olivio | ![]() |
Meaning : Olive Tree Used in : Australian, Portuguese |
| Ordonho | ![]() |
Meaning : Used in : Portuguese |
| Orestes | ![]() |
Meaning : Mother Slept A Lot During Pregnancy Used in : Australian, Greek, Portuguese |
| Oscar | ![]() |
Meaning : Spear Of Strength Used in : American, Australian, Chinese, British, Celtic, Danish, Dutch, English, French, German, Irish, Jamaican, Italian, Norse, Norwegian, Portuguese, Scandinavian, Swedish, Swiss, Australian, Dutch |
| Osorio | ![]() |
Meaning : The Greatest Used in : Portuguese |
| Osvaldo | ![]() |
Meaning : Divine Power Used in : American, Australian, Chinese, British, English, French, German, Italian, Latin, Portuguese |
| Otavio | ![]() |
Meaning : Eighth Used in : Portuguese |
| Ovid | ![]() |
Meaning : She, Woman Used in : Australian, Hebrew, Latin, Portuguese |