| Croton pyriticus Croizat, 1945 |
| Croton quercetorum Croizat, 1942 |
| Croton ramillatus Croizat, 1945 |
| Croton ramillatus var. insignilobus Croizat, 1945 |
| Croton reflexifolius Kunth, 1817 |
| Croton repens Schltdl., 1847 |
| Croton riparius Kunth, 1817 |
| Croton rivinifolius Kunth, 1817 |
| Croton rojasii V.W. Steinm., 2021 |
| Croton rosarianus Mart. Gord. & Cruz Durán, 2002 |
| Croton roxanae Croizat, 1940 |
| Croton rzedowskii M.C. Johnst., 1968 |
| Croton salvifolius Mill., 1768 |
| Croton sancti-lazari Croizat, 1945 |
| Croton sanguifluus Kunth, 1817 |
| Croton scandens Sieber ex C. Presl, 1845 |
| Croton schiedeanus Schltdl., 1847 |
| Croton scordioides Lam., 1786 |
| Croton septemnervius McVaugh, 1961 |
| Croton sericeus Schltdl., 1830 |