| Sciurus leucops J. A. Allen, 1877 |
| Sciurus limitis Baird, 1855 |
| Sciurus ludovicianus Custis, 1806 |
| Sciurus ludovicianus subsp. limitis Baird, 1855 |
| Sciurus mearnsi (Townsend, 1897) |
| Sciurus mexicanus Erxleben, 1777 |
| Sciurus mustelinus Audubon & Bachman, 1841 |
| Sciurus nayaritensis J. A. Allen, 1889 |
| Sciurus nayaritensis subsp. apache J. A. Allen, 1893 |
| Sciurus nayaritensis subsp. nayaritensis J. A. Allen, 1889 |
| Sciurus negligens E. W. Nelson, 1898 |
| Sciurus nelsoni Merriam, 1893 |
| Sciurus nelsoni subsp. hirtus E. W. Nelson, 1898 |
| Sciurus nelsoni subsp. nelsoni Merriam, 1893 |
| Sciurus niger Linnaeus, 1758 |
| Sciurus niger subsp. limitis Baird, 1855 |
| Sciurus niger subsp. ludovicianus Thomas, 1890 |
| Sciurus niger subsp. melanonetus Thomas, 1890 |
| Sciurus nigrescens Bennett, 1833 |
| Sciurus oculatus Peters, 1863 |