| Oryzomys rostratus subsp. megadon Merriam, 1901 |
| Oryzomys rostratus subsp. rostratus Merriam, 1901 |
| Oryzomys rostratus subsp. yucatanensis Merriam, 1901 |
| Oryzomys rufus Merriam, 1901 |
| Oryzomys saturatior Merriam, 1901 |
| Oryzomys saturatior subsp. hylocetes Merriam, 1901 |
| Oryzomys saturatior subsp. saturatior Merriam, 1901 |
| Oryzomys teapensis Merriam, 1901 |
| Oryzomys texensis J. A. Allen, 1894 |
| Oryzomys yucatanensis Merriam, 1901 |
| Oryzomys zygomaticus Merriam, 1901 |
| Osgoodomys Hooper & Musser, 1964 |
| Osgoodomys banderanus (J. A. Allen, 1897) |
| Osgoodomys banderanus subsp. banderanus (J. A. Allen, 1897) |
| Osgoodomys banderanus subsp. vicinior (Osgood, 1904) |
| Otonyctomys Anthony, 1932 |
| Otonyctomys hatti Anthony, 1932 |
| Ototylomys Merriam, 1901 |
| Ototylomys brevirostris Laurie, 1953 |
| Ototylomys brevirostris subsp. affinis Laurie, 1953 |