| Reported in | Status | Registered by | ||
|---|---|---|---|---|
| Ottowia caeni | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oscillospira | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oscillospira guilliermondii T | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oscillospira guilliermondi | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oscillochloris chrysea T | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oscillibacter hominis | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oscillibacter acetigenes | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oryzomonas ruber | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oryzomonas japonicum | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Orrella marina | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Orrella daihaiensis | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ornithinimicrobium laminariae | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ornithinimicrobium ciconiae | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ornithinimicrobium avium | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oricola indica | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oribaculum | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oribaculum catoniae T | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Olsenella scatoligenes | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oligotropha | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oligotropha carboxidovorans T | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Oerskovia xanthineolytica | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Octadecabacter jejudonensis | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Octadecabacter dasysiphoniae | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Octadecabacter algicola | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ochrobactrum tritici | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ochrobactrum thiophenivorans | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ochrobactrum rhizosphaerae | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ochrobactrum pseudogrignonense | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ochrobactrum pseudintermedium | Unknown | Valid (ICNP) | Excubia bot over 3 years ago | |
| Ochrobactrum pituitosum | Unknown | Valid (ICNP) | Excubia bot over 3 years ago |