A huge list of positive words, adjectives and verbs starting with the letter O.
| Optimism | Optimistic | Open |
| Open-minded | Okay | Opportunity |
| Outstanding | Open-hearted | Optimal |
| Observant | Observe | Official |
| Overflowing | Operative | Obey |
| Obedience | Obviousness | Opulent |
| Option | Original | Originality |
| Obedient | Oneness | Outright |
| Openness | Offer | Obtain |
