| Eupatorium corvi McVaugh, 1972 |
| Eupatorium costaricense Kuntze, 1891 |
| Eupatorium coulteri B.L. Rob., 1901 |
| Eupatorium crassirameum B.L. Rob., 1900 |
| Eupatorium cremastum B.L. Rob., 1906 |
| Eupatorium crenaeum B.L. Rob., 1900 |
| Eupatorium critoniforme Urb., 1899 |
| Eupatorium critonioides Steetz, 1854 |
| Eupatorium cronquistii (R.M. King & H. Rob.) B.L. Turner, 1989 |
| Eupatorium cupressorum Standl. & Steyerm., 1944 |
| Eupatorium cuspidatum Willd. ex Less., 1829 |
| Eupatorium cylindricum McVaugh, 1972 |
| Eupatorium cymuliferum (B.L. Rob.) B.L. Turner, 1989 |
| Eupatorium daleoides (DC.) Hemsl., 1881 |
| Eupatorium dasycarpum A. Gray ex S. Watson, 1887 |
| Eupatorium decussatum Klatt, 1896 |
| Eupatorium deltoideum Jacq., 1798 |
| Eupatorium denticulatum Vahl, 1794 |
| Eupatorium desquamans B.L. Rob., 1900 |
| Eupatorium dibollii (R.M. King & H. Rob.) B.L. Turner, 1989 |