| Eupatorium palmeri A. Gray, 1886 |
| Eupatorium paneroi (B.L. Turner) B.L. Turner, 1997 |
| Eupatorium paniculatum Mill., 1768 |
| Eupatorium pansamalense B.L. Rob., 1901 |
| Eupatorium papantlense Less., 1831 |
| Eupatorium parayanum Espinosa, 1984 |
| Eupatorium parryi A. Gray, 1859 |
| Eupatorium pauperculum A. Gray, 1882 |
| Eupatorium pazcuarense Kunth, 1818 |
| Eupatorium pedunculosum (DC.) A. Gray, 1852 |
| Eupatorium pelotrophum B.L. Rob., 1906 |
| Eupatorium pendulum Schrad., 1830 |
| Eupatorium peninsulare Brandegee, 1899 |
| Eupatorium peninsulare var. epipolimum B.L. Rob., 1924 |
| Eupatorium perornatum Klatt, 1884 |
| Eupatorium perpetiolatum (R.M. King & H. Rob.) L.O. Williams, 1975 |
| Eupatorium petasites Griseb., 1877 |
| Eupatorium petiolare Moc. & Sessé ex DC., 1836 |
| Eupatorium petraeum B.L. Rob., 1905 |
| Eupatorium phanioides Urb. & Ekman, 1931 |