Ordered by the number of ascents recorded.
| Climb Name | Type | Grade | # Ascents Recorded | Notes | Exclude Reason |
|---|---|---|---|---|---|
| Øgletryne | Sport route | 8a | 1 | ||
| Ogwen Crack | Trad climb | E7 | 1 | ||
| Oh Saint Léger Fait Moi Monter au Relais | Sport route | 8a+ | 1 | ||
| Oiran | Boulder problem | 8B+ | 1 | ||
| Oisiiyo | Sport route | 7c+ | 1 | ||
| Okachi | Sport route | 9a+ | 1 | ||
| Oksespranget | Boulder problem | 8A | 1 | ||
| Okuro | Boulder problem | 8C | 1 | ||
| Old Boy Racer | Trad climb | E8 | 1 | ||
| Old Fogey Direct | Trad climb | E5 | 1 | ||
| Old King Cole | Trad climb | E6 | 1 | ||
| Old Milwaukee | Boulder problem | 8B+ | 1 | ||
| Olion | Boulder problem | 8A+ | 1 | ||
| Olympiad | Trad climb | E10 | 1 | ||
| Olympus Trip | Trad climb | E6 | 1 | ||
| Omen | Trad climb | E6 | 1 | ||
| Omnipotence | Trad climb | E7 | 1 | ||
| Onde de Choc | Boulder problem | 7B | 1 | ||
| Onde O Sol Não Toca | Boulder problem | 8B+ | 1 | ||
| One 'ard Move | Trad climb | E6 | 1 |