| Orlandia Comellini, 1985 |
| Orlandia parki Comellini, 1985 |
| Oropodes Casey, 1894 |
| Oropodes tipai Chandler & Caterino, 2011 |
| Orus Casey, 1885 |
| Orus (Leucorus) Casey, 1905 |
| Orus (Nivorus) Herman, 1965 |
| Orus (Pycnorus) Casey, 1905 |
| Osoriellus Fagel, 1959 |
| Osoriellus cordovensis (Bernhauer, 1910) |
| Osoriina Erichson, 1839 |
| Osoriinae Erichson, 1839 |
| Osoriini Erichson, 1839 |
| Osorius Guérin-Méneville, 1829 |
| Osorius asymetricus Fauvel, 1901 |
| Osorius brasiliensis Guérin-Meneville, 1829 |
| Osorius brevicornis Notman, 1920 |
| Osorius brevipennis Notman, 1925 |
| Osorius canaliculatus Solsky, 1870 |
| Osorius confusus Notman, 1925 |