| Obadiah | servant of the Lord |
| Obal | inconvenience of old age |
| Obed | a servant; workman |
| Obed-edom | servant of Edom |
| Obil | that weeps; who deserves to be bewailed |
| Oboth | dragons; fathers; desires |
| Ocran | a disturber; that disorders |
| Oded | to sustain hold or lift up |
| Og | a cake; bread baked in ashes |
| Ohad | praising; confessing |
| Ohel | tent; tabernacle; brightness |
| Olympas | heavenly |
| Omar | he that speaks; bitter |
| Omega | the last letter of the Greek alphabet; long O |
| Omri | sheaf of corn |
| On | pain; force; iniquity |
| Onam | Onan same as On |
| Onesimus | profitable; useful |
| Onesiphorus | who brings profit |
| Ono | grief or strength or iniquity of him |
| Ophel | a tower; darkness; small white cloud |
| Ophir | fruitful region |
| Ophni | wearisomeness; folding together |
| Ophrah | dust; lead; a fawn |
| Oreb | a raven |
| Ornan | that rejoices |
| Orpah | the neck or skull |
| Oshea | same as Joshua |
| Othni | my time; my hour |
| Othniel | the hour of God |
| Ozem | that fasts; their eagerness |
| Ozias | strength from the Lord |
| Ozni | an ear; my hearkening |