A
- Winston Abreu
- Jonathan Albaladejo
- Santo Alcalá
- Scott Aldred
- Mike Aldrete
- Bernie Allen
- Bill Almon
- Héctor Almonte
- Felipe Alou
- Moisés Alou
- Tavo Alvarez
- Marlon Anderson
- Scott Anderson
- Shane Andrews
- Rick Ankiel
- Luis Aquino
- Tony Armas, Jr.
- Pedro Astacio
- Luis Atilano
- Bill Atkinson
- Derek Aucoin
- Bobby Ayala
- Luis Ayala
Read more about this topic: Washington Nationals All-time Roster