| Onychomys ruidosae Stone & Rehn, 1903 |
| Onychomys torridus (Coues, 1874) |
| Onychomys torridus subsp. arenicola Mearns, 1896 |
| Onychomys torridus subsp. ater S. Anderson, 1972 |
| Onychomys torridus subsp. canus Merriam, 1904 |
| Onychomys torridus subsp. knoxjonesi Hollander & Willig, 1992 |
| Onychomys torridus subsp. macrotis Elliot, 1903 |
| Onychomys torridus subsp. perpallidus Mearns, 1896 |
| Onychomys torridus subsp. pulcher Elliot, 1904 |
| Onychomys torridus subsp. ramona Rhoads, 1893 |
| Onychomys torridus subsp. surrufus Hollister, 1914 |
| Onychomys torridus subsp. torridus (Coues, 1874) |
| Onychomys torridus subsp. yakiensis Merriam, 1904 |
| Orthriomys Merriam, 1898 |
| Orthriomys umbrosus (Merriam, 1898) |
| Oryzomys Baird, 1858 |
| Oryzomys albiventer Merriam, 1901 |
| Oryzomys alfaroi (J. A. Allen, 1891) |
| Oryzomys alfaroi subsp. agrestis Goodwin, 1959 |
| Oryzomys alfaroi subsp. angusticeps Merriam, 1901 |