| Croton aguilarii Lundell, 1940 |
| Croton alamosanus Rose, 1891 |
| Croton albinoides (A.M. Ferguson) Croizat, 1942 |
| Croton alvaradonis M.E. Jones, 1933 |
| Croton ameliae Lundell, 1940 |
| Croton amphileucus Briq., 1900 |
| Croton arboreus Millsp., 1896 |
| Croton argenteus L., 1753 |
| Croton argyranthemus Michx., 1803 |
| Croton aridicola Urb., 1912 |
| Croton asteroides Lundell, 1940 |
| Croton astroites Willd., 1805 |
| Croton atrostellatus V.W. Steinm., 2005 |
| Croton attenuatus M.E. Jones, 1933 |
| Croton atwoodianus F. Seym., 1979 |
| Croton avenius Geiseler, 1807 |
| Croton axillaris Müll. Arg., 1865 |
| Croton balsensis V.W. Steinm. & Mart. Gord., 2007 |
| Croton berlandieri Torr., 1858 |
| Croton billbergianus Müll. Arg., 1865 |