| Orimodema Horn, 1876 |
| Orimodema protracta Horn, 1876 |
| Orthomerinus Champion, 1908 |
| Orthomerinus pittieri Champion, 1908 |
| Orthoptochus Casey, 1888 |
| Orthoptochus squamiger Casey, 1888 |
| Orthoris LeConte, 1876 |
| Orthoris cylindrifer Casey, 1892 |
| Otidocephalini Lacordaire, 1863 |
| Otiorhynchini Schönherr, 1826 |
| Otiorhynchus Germar, 1822 |
| Otiorhynchus cribricollis Gyllenhal, 1834 |
| Otiorhynchus rugosostriatus (Goeze, 1777) |
| Oxytenopterus Berg, 1898 |
| Oxytenopterus clotho (Kirsch, 1869) |
| Oxytenopterus denticollis (Champion, 1905) |
| Oxytenopterus fausti (Champion, 1905) |
| Oxytenopterus rubigibosus (Champion, 1905) |
| Oxytenopterus terminatus (Champion, 1905) |
| Pachnaeus Schönherr, 1826 |