| Solanum sideroxyloides Schltdl., 1833 |
| Solanum sideroxyloides subsp. ocellata Bitter, 1919 |
| Solanum sideroxyloides var. ocellatum Donn. Sm., 1889 |
| Solanum siparunoides Ewan, 1952 |
| Solanum solitarium S.F. Blake, 1922 |
| Solanum somniculentum Schltdl., 1847 |
| Solanum sousae S. Knapp, 2010 |
| Solanum spectabile Sendtn., 1954 |
| Solanum splendens (Dunal) Bohs, 2015 |
| Solanum squamulosum M. Martens & Galeotti, 1845 |
| Solanum stellatum Ruiz & Pav., 1799 |
| Solanum stephanocalyx Brandegee, 1917 |
| Solanum sylvicola Brandegee, 1917 |
| Solanum symphysicaulis Pav. ex Dunal, 1852 |
| Solanum synantherum Sendtn., 1846 |
| Solanum tampicense Dunal, 1852 |
| Solanum tarapotense Van Heurck & Müll. Arg., 1870 |
| Solanum tenellum Bitter, 1912 |
| Solanum tenuilobatum Parish, 1901 |
| Solanum tequilense A. Gray, 1887 |