| osäkerhet | doubt |
| Osäkerhetsprincipen | Uncertainty principle |
| osäkring | cocking |
| osällskaplig | antisocial |
| osårbar | invulnerable |
| osårbarhet | invulnerability |
| osötad | unsweetened |
| OT | OT |
| Otachon Latifi | Otakhon Latifi |
| Otaci | Otaci |
| otacksam | ungrateful |
| otacksamhet | ingratitude |
| otadlig | flawless |
| otalig | incalculable |
| otaliga | numerous |
| Otanes | Otanes |
| Otecknad | Live action |
| Otello | Otello |
| Otello ossia Il moro di Venezia | Otello |
| Otep | OTEP |
| Otepää | Otepää |
| Othello | Othello |
| Other Voices | Other Voices |
| Othmarsingen | Othmarsingen |
| Othniel Charles Marsh | Othniel Charles Marsh |
| Otho | Otho |
| otillbörlig | unseemly |
| otillbörligt | unduly |
| otillfredsställande | unsatisfactory |
| otillförlitlighet | unreliability |
| otillgänglig | remote |
| otillgänglighet | inaccessibility |
| otillräcklig | deficient |
| otillräcklighet | inadequacy |
| otillräknelig | non compos mentis |
