| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 1601 | Odile | French | Wealthy. | F | |
| 1602 | Odo | French | Name of a bishop. | M | |
| 1603 | Oliver | French | The olive tree. The biblical olive tree symbolizes fruitfulness and beauty and dignity. Extending an olive branch signifies an offer of peace. | M | |
| 1604 | Olivier | French | From the olive tree. | M | |
| 1605 | Ollie | French | Diminutive of Oliver: Olive tree. | M | |
| 1606 | Olympe | French | From Olympus. | F | |
| 1607 | Olympia | French | From Olympus. | F | |
| 1608 | Onfroi | French | PeacefuI Hun. | M | |
| 1609 | ONille | French | From the gold town. | M | |
| 1610 | Ophelia | French | Serpentine. | F | |
| 1611 | Ophelie | French | Serpentine. | F | |
| 1612 | Orane | French | Rising. | F | |
| 1613 | Oriel | French | Bird. | F | |
| 1614 | Orlena | French | Gold. | F | |
| 1615 | Orlene | French | Gold. | F | |
| 1616 | Orlina | French | Gold. | F | |
| 1617 | Orson | French | Bear cub. Famous Bearer: American actor/director Orson Welles. | M | |
| 1618 | Orva | French | Worth gold. | F | |
| 1619 | Orval | French | Variant of Orville: Gold town. Famous Bearer: aviator Orville Wright (1871-1948) who (along with his brother Wilbur) designed and built the first true airplane. | M | |
| 1620 | Orvelle | French | Gold town. | M | |