| Session: | 21st |
| Start: | 1997 |
| End: | 2001 |
| President: | Charlie Rodríguez |
| Pro Tempore: | Aníbal Marrero Pérez (1997-2000) Lucy Arce (2000) |
| Majority Leader: | José Enrique Meléndez (PNP) |
| Minority Leader: | Antonio Fas Alzamora (PPD) Rubén Berríos (PIP) |
| Seats: | 28 |
| Non Officers: | 2 |
| Party1: | PNP |
| Party2: | PPD |
| Party3: | PIP |
| Majority: | PNP |
| Legislature: | 13th |
| Lower House: | 25th |
| Session1: | 1st |
| Session1start: | January 14, 1997 |
| Session1end: | January 12, 1998 |
| Session2: | 2nd |
| Session2start: | January 13, 1998 |
| Session2end: | January 11, 1999 |
| Session3: | 3rd |
| Session3start: | January 12, 1999 |
| Session3end: | January 10, 2000 |
| Session4: | 4th |
| Session4start: | January 11, 2000 |
| Session4end: | January 1, 2001 |
| Previous: | 20th |
| Next: | 22nd |
The 21st Senate of Puerto Rico was the upper house of the 13th Legislative Assembly of Puerto Rico that met from January 2, 1997, to January 1, 2001. All members were elected in the General Elections of 1996. The Senate had a majority of members from the New Progressive Party (PNP).
The body is counterparted by the 25th House of Representatives of Puerto Rico in the lower house.
| Position | Name | Party | District | ||
|---|---|---|---|---|---|
| PNP | At-Large | ||||
| PNP | At-Large | ||||
| PNP | VI | ||||
| PNP | |||||
| PPD | At-large | ||||
| PPD |
| width=10 | District ! | Name | Party | |
|---|---|---|---|---|
| I - San Juan | Junior González | PNP | ||
| Jorge Santini | PNP | |||
| II - Bayamón | Aníbal Marrero Pérez | PNP | ||
| Ramón Luis Rivera Jr. | PNP | |||
| III - Arecibo | Norma Carranza | PNP | ||
| Víctor Marrero Padilla | PNP | |||
| nowrap rowspan=2 | IV - Mayagüez-Aguadilla | Carlos Pagán | PNP | |
| Jorge Ramos Comas | PPD | |||
| V - Ponce | Modesto Agosto Alicea | PPD | ||
| Bruno Ramos | PPD | |||
| VI - Guayama | Carmen Luz Berríos | PNP | ||
| José Enrique Meléndez | PNP | |||
| VII - Humacao | Carlos Dávila López | PNP | ||
| Luis Felipe Navas | PNP | |||
| VIII - Carolina | Roger Iglesias | PNP | ||
| Luisa Lebrón | PNP | |||
| At-Large | PNP | |||
| PPD | ||||
| PIP | ||||
| PPD | ||||
| PPD | ||||
| PPD | ||||
| PNP | ||||
| PPD | ||||
| PNP | ||||
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| PNP |