A
- David Aardsma
- Don Aase
- Andy Abad
- Alfredo Aceves
- Jerry Adair
- Bob Adams
- Terry Adams
- Doc Adkins
- Benny Agbayani
- Harry Agganis
- Sam Agnew
- Rick Aguilera
- Matt Albers
- Izzy Alcántara
- Dale Alexander
- Manny Alexander
- Luis Alicea
- Gary Allenson
- Mel Almada
- Héctor Almonte
- Nick Altrock
- Luis Alvarado
- Abe Alvarez
- Larry Andersen
- Brady Anderson
- Brian Anderson
- Fred Anderson
- Jimmy Anderson
- Lars Anderson
- Ernie Andres
- Kim Andrew
- Ivy Andrews
- Mike Andrews
- Shane Andrews
- Luis Aparicio
- Luis Aponte
- Pete Appleton
- Frank Arellanes
- Tony Armas
- Charlie Armbruster
- Rolando Arrojo
- Bronson Arroyo
- Casper Asbjornson
- Billy Ashley
- Ken Aspromonte
- Pedro Astacio
- Scott Atchison
- James Atkins
- Elden Auker
- Leslie Aulds
- Steve Avery
- Bobby Ávila
- Ramón Avilés
- Mike Avilés
- Joe Azcue
Read more about this topic: Boston Red Sox All-time Roster