| 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 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 |
| Piper unguiculatum Ruiz & Pav., 1798 |
| Piper uspantanense C. DC. ex Donn. Sm., 1894 |
| Piper usumacintense Lundell, 1941 |
| Piper variabile C. DC., 1894 |
| Piper variegatum (Ruiz & Pav.) Pers., 1805 |
| Piper variifolium (Miq.) C. DC., 1869 |
| Piper velutinovarium C. DC., 1920 |
| Piper veraguense C. DC., 1869 |