| Psychotria oaxacana Standl., 1926 |
| Psychotria oaxacensis Borhidi & Salas-Mor., 2009 |
| Psychotria obovata (Oerst.) Hemsl., 1881 |
| Psychotria oerstediana Standl., 1926 |
| Psychotria officinalis (Aubl.) Raeusch. ex Sandwith, 1931 |
| Psychotria orchidearum Standl., 1928 |
| Psychotria oreodoxa L.O. Williams, 1974 |
| Psychotria orogenes L.O. Williams, 1974 |
| Psychotria pachecoana Standl. & Steyerm., 1940 |
| Psychotria padifolia Willd. ex Roem. & Schult., 1819 |
| Psychotria panamensis Standl., 1916 |
| Psychotria panamensis var. ixtlanensis C.W. Ham., 1988 |
| Psychotria panamensis var. panamensis Standl., 1916 |
| Psychotria papantlensis (Oerst.) Hemsl., 1881 |
| Psychotria parasitica Sw., 1788 |
| Psychotria patens Sw., 1788 |
| Psychotria pavetta Sw., 1788 |
| Psychotria pendula (Jacq.) Urb., 1880 |
| Psychotria pendula subsp. tetrapyrena Urb., 1899 |
| Psychotria perotensis Cast.-Campos, 2009 |