List of almost 150 positive words that start with O letter
| O.K. | On Hand | Opportune | Opportune |
| Oasis | On My Wavelength | Opportunely | Opportunely |
| Obedient | On Target | Opportunity | Opportunity |
| Objective | On The Ball | Optate | Optate |
| Objectively | On The Beam | Optimal | Optimal |
| Oblige | On The Button | Optimally | Optimally |
| Obliged | On The Money | Optimism | Optimism |
| Obliging | On The Right Foot | Optimist | Optimist |
| Obligingly | Once | Optimistic | Optimistic |
| Observant | One | Optimistically | Optimistically |
| Observantly | One-Hundred Percent | Optimum | Optimum |
| Observe | Oneness | Opulent | Opulent |
| Obsession | One-Pointedness | Opulently | Opulently |
| Obsessions | On-The-Job | Orchestrator | Orchestrator |
| Obtain | Onward | Order | Order |
| Obtainable | Onwards | Orderly | Orderly |
| Occur | Oodles | Orenda | Orenda |
| Oecumenical | Ooh | Organic | Organic |
| Offer | Oohlala! | Organization | Organization |
| Officer | Oomph | Organize | Organize |
| Official | Oopsey | Organized | Organized |
| Offspring | Ooze | Organizer | Organizer |
| Oh | Open | Orientate | Orientate |
| Oh My | Open Hearted | Orientation | Orientation |
| Oho | Open-Handed | Oriented | Oriented |
| Oh-Oh | Open-Handedly | Original | Original |
| Ok | Openhearted | Originality | Originality |
| Okay | Open-Hearted | Originally | Originally |
| Okayed | Open-Heartedly | Originate | Originate |
| Okey-Dokey | Opening | Originator | Originator |
| Olé | Openly | Ornamental | Ornamental |
| Olympian | Open-Minded | Oscillate | Oscillate |
| Om | Open-Mindedly | Osculate | Osculate |
| Om Mani Padme Hum | Openness | Outcome | Outcome |
| Omg | Operate | Outdo | Outdo |
| Omnipotent | Operative | Outdone | Outdone |
| On | Operator | Outernationalist | Outernationalist |