| Onthophagus Latreille, 1802 |
| Onthophagus acuminatus Harold, 1880 |
| Onthophagus alluvius Howden & Cartwright, 1963 |
| Onthophagus altivagans Howden & Génier, 2004 |
| Onthophagus anewtoni Howden & Génier, 2004 |
| Onthophagus anthracinus Harold, 1873 |
| Onthophagus asperodorsatus Howden & Gill, 1993 |
| Onthophagus atriglabrus Howden & Gill, 1987 |
| Onthophagus aureofuscus Bates, 1887 |
| Onthophagus aztecus Zunino & Halffter, 1988 |
| Onthophagus bajacalifornianus Moctezuma & Halffter, 2019 |
| Onthophagus bassariscus Zunino & Halffter, 1988 |
| Onthophagus batesi Howden & Cartwright, 1963 |
| Onthophagus belorhinus Bates, 1887 |
| Onthophagus bolivari Moctezuma, Rossini & Zunino, 2016 |
| Onthophagus brachypterus Zunino & Halffter, 1997 |
| Onthophagus brevifrons Horn, 1881 |
| Onthophagus browni Howden & Cartwright, 1963 |
| Onthophagus canelasensis Howden & Génier, 2004 |
| Onthophagus canescens Zunino & Halffter, 1988 |