Starting with letter O
| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 281 | Orsino | Shakespearean | 'Twelfth Night', also called 'What You Will' Orsino, Duke of Illyria. | M | |
| 282 | Orson | English | Ormond's son. | M | |
| 283 | Orson | French | Bear cub. Famous Bearer: American actor/director Orson Welles. | M | |
| 284 | Orson | Latin | Little bear. Actor and director Orson Welles. | M | |
| 285 | Orthros | Greek | Guardian of Geryon. | M | |
| 286 | Orton | English | From the shore farm. | M | |
| 287 | Orton | Teutonic | Rich. | M | |
| 288 | Ortun | English | From the shore farm. | M | |
| 289 | Orval | English | Spear strength. | M | |
| 290 | 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 | |
| 291 | Orvelle | French | Gold town. | M | |
| 292 | Orvil | English | Spear strength. | M | |
| 293 | Orvil | French | Gold town. | M | |
| 294 | Orville | English | Spear strength. | M | |
| 295 | Orville | French | Gold town. Famous Bearer: aviator Orville Wright (1871-1948) who (along with his brother Wilbur) designed and built the first true airplane. | M | |
| 296 | Orvin | Anglo-Saxon | Brave friend. | M | |
| 297 | Orvin | English | Spear friend. | M | |
| 298 | Orvyn | Anglo-Saxon | Brave friend. | M | |
| 299 | Orvyn | English | Spear friend. | M | |
| 300 | Orwald | English | Spear strength. | M | |