| Piper tenue Kunth, 1816 |
| Piper tenuifolium C. DC., 1869 |
| Piper tepicanum C. DC., 1914 |
| Piper terrabanum C. DC., 1892 |
| Piper tetraphyllum G. Forst., 1786 |
| Piper tiliifolium Schltdl. & Cham., 1831 |
| Piper trichophyllum C. DC., 1898 |
| Piper trigonum C. DC., 1866 |
| Piper tuberculatum Jacq., 1792 |
| Piper tuerckheimii C. DC., 1894 |
| Piper tuxpenyana (Trel.) Lundell, 1937 |
| Piper tuxtepecense Trel.ex Callejas, 2020 |
| Piper tuxtlense Callejas, 2020 |
| Piper udicola C. DC., 1920 |
| Piper udimontanum C. DC., 1920 |
| Piper uhdei C. DC., 1869 |
| Piper ulei C. DC., 1898 |
| Piper umbellatum L., 1753 |
| Piper umbilicatum (Ruiz & Pav.) Vahl, 1805 |
| Piper umbricola C. DC., 1891 |