| Oploptera (Oploptera) Chevrolat, 1844 |
| Oploptera (Oploptera) chamelensis (Doyen, 1990) |
| Orthostibia Blaisdell, 1923 |
| Orthostibia fraterna Blaisdell, 1943 |
| Orthostibia frontalis Blaisdell, 1923 |
| Orthostibia muricata Blaisdell, 1943 |
| Otocerus Mäklin, 1867 |
| Otocerus chamelensis Doyen, 1990 |
| Oxidates Champion, 1886 |
| Oxidates aurichalceus Champion, 1887 |
| Oxidates elongatus Champion, 1893 |
| Oxidates gibbus Champion, 1893 |
| Oxidates gravidus (Breme, 1842) |
| Oxidates mexicanus (Breme, 1842) |
| Oxidates planicollis Champion, 1886 |
| Oxidates princeps Champion, 1887 |
| Oxidates puncticeps Champion, 1887 |
| Oxidates thoracicus (Breme, 1842) |
| Oxinthas Champion, 1884 |
| Oxinthas praocioides Champion, 1884 |