| Name | Meaning | Gender | Origin |
|---|
| Mani | Jewel | Unisex | Hindi |
| Mar | | Unisex | |
| Mikkel | Who Is Like God | Unisex | Scandinavian |
| Njord | Viking mythology: the god of wind and sea | Male | Scandinavian |
| Norbert | blond hero | Male | |
| Odd | Sword's Point | Unisex | Norwegian |
| Odin | Viking mythology: the allmighty god | Male | Old |
| Olaf | ancestor's relic | Male | Norse |
| Oliver | The olive tree. The biblical olive tree symbolizes fruitfulness and beauty and dignity. Extending an olive branch signifies an offer of peace.
| Male | Latin |
| Osborn | Soldier of God | Male | English |
| Osborne | soldier of God | Unisex | |
| Oscar | God's spear.
| Male | English |
| Osgood | divine creator | Male | Teutonic |
| Oskar | English, God's spear, Irish, deer-lover or champion warrior | Male | |
| Quimby | from the woman's estate | Male | Norse |
| Ran | Lily, Purity | Unisex | Japanese |
| Rick | aka Richard, Dick and Little Man | Male | English |
| Ricky | dominant or peaceful ruler | Male | English |
| Roar | | Unisex | |
| Rolf | Fame, Wolf | Unisex | German |
| Roscoe | From the deer forest. | Male | Norse |
| Sigmund | Victory: protection. Austrian psychologist Sigmund Freud.
| Male | |
| Sigurd | Victorious Guardian | Unisex | Scandinavian |
| Snorri | | Unisex | Hebrew |
| Stigr | | Unisex | Hebrew |