| # | Name | Origin | Meaning | Gender | Save |
|---|---|---|---|---|---|
| 5081 | Ollaneg | English | From Olney. | M | |
| 5082 | Olney | English | From Olney. | M | |
| 5083 | Onslow | English | From the zealous one's hill. | M | |
| 5084 | Onslowe | English | From the zealous one's hill. | M | |
| 5085 | Oona | English | One. | F | |
| 5086 | Opal | English | Opal (precious stone). Jewel names became popular in the 19th century. | F | |
| 5087 | Ora | English | Beautiful seacoast. | F | |
| 5088 | Orabel | English | Beautiful seacoast. | F | |
| 5089 | Orabelle | English | Beautiful seacoast. | F | |
| 5090 | Orahamm | English | From tbe riverbank enclosure. | M | |
| 5091 | Oralie | English | Golden. | F | |
| 5092 | Oram | English | From tbe riverbank enclosure. | M | |
| 5093 | Oratun | English | From the shore farm. | M | |
| 5094 | Ordland | English | From the pointed hill. | M | |
| 5095 | Ordman | English | Spearman. | M | |
| 5096 | Ordmund | English | Spear defender. | M | |
| 5097 | Ordsone | English | Ormond's son. | M | |
| 5098 | Ordwald | English | Spear strength. | M | |
| 5099 | Ordwin | English | Spear friend. | M | |
| 5100 | Ordwine | English | Spear friend. | M | |