| Name | Sex | Language | Meaning(s) | Original Spelling | Notes |
|---|
| Ons | Male | Arabic 10801 names | Meaning(s) of Ons: Gladness 5 names | أَنِس | |
| Onshuda | Female | Arabic 10801 names | Meaning(s) of Onshuda: Chant 2 names Hymn 2 names | أُنشُودة | |
| Onsi | Male | Arabic 10801 names | Meaning(s) of Onsi: Bringer of Calm and Gladness 4 names | أُنْسِي | |
| Onsiyah | Female | Arabic 10801 names | Meaning(s) of Onsiyah: Bringer of Calm and Gladness 4 names | أُنْسِيَّة | |
| Oola | Female | Arabic 10801 names | Meaning(s) of Oola: First 9 names Foremost 4 names | أُوْلَى | Variant of the name Oula, which is mentioned in the Quran. |
| Opal | Female | English 773 names | Meaning(s) of Opal: Opal 2 names | | Opal is a type of gemstone. |
| Opaline | Female | English 773 names | Meaning(s) of Opaline: Opal 2 names | | Elaboration of Opal. |
| Oraib | Unisex | Arabic 10801 names | Meaning(s) of Oraib: Intelligent 181 names Keen 24 names Perceptive 68 names | أُرَيْب | |
| Oraiba | Female | Arabic 10801 names | Meaning(s) of Oraiba: Intelligent 181 names Keen 24 names Perceptive 68 names | أُرَيْبَة | |
| Oraibi | Male | Arabic 10801 names | Meaning(s) of Oraibi: Intelligent 181 names Keen 24 names Perceptive 68 names | أُرَيْبِي | |
| Oraibia | Female | Arabic 10801 names | Meaning(s) of Oraibia: Intelligent 181 names Keen 24 names Perceptive 68 names | أُرَيْبِيَّة | |
| Orang | Male | Persian 2045 names | Meaning(s) of Orang: Throne 4 names | اورنگ | |
| Orell | Male | Swiss 2 names | Meaning(s) of Orell: Golden 17 names | | Form of Aurelius. |
| Orhaan | Male | Turkish 166 names | Meaning(s) of Orhaan: Great Leader 4 names | | Variant of the name Orhan. |
| Orhan | Male | Turkish 166 names | Meaning(s) of Orhan: Great Leader 4 names | | |
| Orkhaan | Male | Turkish 166 names | Meaning(s) of Orkhaan: Great Leader 4 names | أُوْرْخان | Variant of the name Orkhan. |
| Orkhan | Male | Turkish 166 names | Meaning(s) of Orkhan: Great Leader 4 names | أُوْرْخان | |
| Orla | Female | Irish 84 names | Meaning(s) of Orla: Golden Lady 1 names Golden Princess 1 names | | |
| Orlando | Male | Italian 145 names | Meaning(s) of Orlando: Famous Land 5 names | | Italian form of Roland. |
| Ornella | Female | Italian 145 names | Meaning(s) of Ornella: Flowering Ash Tree 2 names | | |
| Ornetta | Female | Italian 145 names | Meaning(s) of Ornetta: Flowering Ash Tree 2 names | | |
| Orson | Male | English 773 names | Meaning(s) of Orson: Bear-cub 2 names | | |
| Orwa | Unisex | Arabic 10801 names | Meaning(s) of Orwa: Ever-green Tree 4 names Handhold 4 names Lion 105 names | عُروة | Variant of the name Urwah, which is mentioned in the Quran. |
| Orwah | Unisex | Arabic 10801 names | Meaning(s) of Orwah: Ever-green Tree 4 names Handhold 4 names Lion 105 names | عُروة | Variant of the name Urwah, which is mentioned in the Quran. |
| Orz | Male | Arabic 10801 names | Meaning(s) of Orz: Proximity 4 names Side 5 names | عُرْض | |
| Orzah | Female | Arabic 10801 names | Meaning(s) of Orzah: Competent 7 names Proactive 1 names | عُرْضَة | |
| Osaim | Male | Arabic 10801 names | Meaning(s) of Osaim: Guardian 56 names Protector 69 names Refuge 11 names | عُصيم | Variant of the name Usaim. |
| Osaym | Male | Arabic 10801 names | Meaning(s) of Osaym: Guardian 56 names Protector 69 names Refuge 11 names | عُصيم | Variant of the name Usaim. |
| Osborn | Male | English 773 names | Meaning(s) of Osborn: Bear of God 3 names Warrior of God 3 names | | |
| Osborne | Male | English 773 names | Meaning(s) of Osborne: Bear of God 3 names Warrior of God 3 names | | Variant of the name Osborn. |
| Osbourne | Male | English 773 names | Meaning(s) of Osbourne: Bear of God 3 names Warrior of God 3 names | | Variant of the name Osborn. |
| Oscar | Male | English 773 names Irish 84 names | Meaning(s) of Oscar: Friend of Deer 2 names | | |
| Osheen | Male | Irish 84 names | Meaning(s) of Osheen: Little Deer 1 names | | |
| Osip | Male | Russian 86 names | Meaning(s) of Osip: (God) Shall Add (Another Son) 1 names | | Form of Joseph. |
| Osmond | Male | English 773 names | Meaning(s) of Osmond: Protected by God 3 names | | |
| Osmund | Male | English 773 names | Meaning(s) of Osmund: Protected by God 3 names | | Variant of the name Osmond. |
| Oswald | Male | English 773 names | Meaning(s) of Oswald: Rule of God 1 names | | |
| Oswin | Male | English 773 names | Meaning(s) of Oswin: Friend of God 3 names | | |
| Otilie | Female | Czech 29 names | Meaning(s) of Otilie: Prosperous 78 names | | Form of Ottilie. |
| Ottavio | Male | Italian 145 names | Meaning(s) of Ottavio: Eighth 3 names | | Form of Octavius. |
| Ottilie | Female | French 120 names German 170 names | Meaning(s) of Ottilie: Prosperous 78 names | | |
| Otto | Male | German 170 names | Meaning(s) of Otto: Prosperous 78 names | | |
| Ottoline | Female | English 773 names French 120 names | Meaning(s) of Ottoline: Prosperous 78 names | | Diminutive form of Ottilie. |
| Otylia | Female | Polish 52 names | Meaning(s) of Otylia: Prosperous 78 names | | Form of Ottilie. |
| Ouhood | Female | Arabic 10801 names | Meaning(s) of Ouhood: Promises 2 names | عُهُوْد | |
| Oula | Female | Arabic 10801 names | Meaning(s) of Oula: First 9 names Foremost 4 names | أُوْلَى | The name Oula is mentioned in the Quran. |
| Oulaa | Female | Arabic 10801 names | Meaning(s) of Oulaa: First 9 names Foremost 4 names | أُوْلَى | Variant of the name Oula, which is mentioned in the Quran. |
| Oumaima | Female | Arabic 10801 names | Meaning(s) of Oumaima: Mother 6 names | أُمَيْمة | Variant of the name Umaima. |
| Oumama | Female | Arabic 10801 names | Meaning(s) of Oumama: Three Hundred Camels 4 names | أُمامة | Variant of the name Umamah. |
| Ovadia | Male | Jewish 12 names | Meaning(s) of Ovadia: Servant of God 231 names | | Modern Hebrew form of Obadiah. |
