| Name | State | School | Class | Pos. | Commitment |
| Tom Aaron | PA | Perkiomen School | 2015 | 3B | University of the Science |
| Mark Aaronson | PA | Friends Select | 2021 | RHP | Rochester |
| Parker Abate | PA | Malvern Prep | 2015 | OF | Misericordia |
| Mason Abate | PA | Malvern Prep | 2016 | RHP | Elizabethtown College |
| Julian Abreu | PA | Friends Central School | 2023 | SS | Marist |
| Mason Abromitis | PA | Allentown Central Catholic | 2022 | SS | Elon |
| Nick Ackerman | PA | West Mifflin | 2018 | C | Pittsburgh-Greensburg |
| Zach Adamchick | PA | Bloomsburg Area | 2017 | LHP | Wilkes University |
| Joe Adametz | PA | Governor Mifflin | 2018 | LHP | Liberty |
| T.J. Adams | PA | Central Cambria | 2016 | OF | Indiana University (PA) |
| Daniel Adams | PA | State College Area | 2018 | SS | McGill University |
| Jeremy Adams | PA | Bishop McCort | 2014 | 2B | Westmoreland County CC |
| Michael Adams | PA | Cumberland Valley | 2014 | RHP | Albany |
| Conner Adams | PA | Wellsboro | 2023 | 2B | Mansfield |
| Greg Adams | PA | Garnet Valley | 2020 | RHP | Penn State-Brandywine |
| Asa Adams | PA | Knoch | 2015 | C | Baldwin Wallace |
| Chris Adams | PA | State College | 2016 | 2B | Pennsylvania |
| Joe Addvensky | PA | Delaware Valley | 2014 | OF | Widener University |
| Darius Adkins | PA | Friends Central School | 2023 | OF | Saint Joseph's |
| Justin Afflerbach | PA | Parkland | 2015 | 3B | Kutztown University |
| Noah Aftanas | PA | Valley | 2017 | SS | Saint Vincent |
| Justus Agosto | PA | Neshaminy | 2021 | RHP | New Orleans |
| RJ Agriss | PA | North Penn | 2021 | 3B | Elizabethtown College |
| Patrick Ahearn | PA | Cardinal O'hara | 2023 | RHP | Albright College |
| Colin Ahr | PA | Dallastown | 2022 | LHP | Seton Hill |
| John Aiello | PA | Germantown Academy | 2015 | 3B | Wake Forest |
| Kyle Ajjan | PA | Downingtown East | 2015 | LHP | Monmouth |
| Mason Akers | PA | Everett Area | 2017 | RHP | Point Park University |
| Brett Alaimo | PA | Manheim Township | 2016 | RHP | Bloomsburg University |
| Jonathan Albers | PA | Corry | 2023 | RHP | Westminster College (PA) |
| Cooper Albert | PA | State College Area | 2023 | RHP | Ithaca College |
| Easton Albert | PA | Boyertown | 2024 | SS | East Stroudsburg |
| Eddie Albert | PA | Upper St. Clair | 2022 | RHP | Dartmouth |
| Brian Albert | PA | Plum | 2015 | RHP | Indiana University (PA) |
| Ed Albertson | PA | Liberty | 2013 | RHP | Northampton CC |
| Colin Albright | PA | Ephrata | 2014 | C | Lebanon Valley College |
| Chaise Albus | PA | Bethlehem Catholic | 2022 | OF | East Stroudsburg |
| Adam Aldenderfer | PA | Williamsport Area | 2023 | C | Garrett JC |
| Zach Alderfer | PA | Perkiomen Valley | 2021 | OF | Penn State Harrisburg |
| Steve Aldrich | PA | Bensalem | 2018 | RHP | Monmouth |
| Christian Aldrich | PA | Pittsburgh Central Catholic | 2016 | 1B | Thiel College |
| Anthony Alesi | PA | Franklin Regional | 2023 | 1B | Patrick Henry CC |
| Max Alessi | PA | Wallenpaupack | 2018 | C | Felician College |
| Dallas Alexander | PA | Central Mountain | 2023 | LHP | Lebanon Valley College |
| Tyler Alexander | PA | Portage Area | 2022 | OF | Delgado CC |
| Brady Alexander | PA | Shaler Area | 2024 | 1B | Ohio |
| A.J. Alexy | PA | Twin Valley | 2016 | RHP | Radford |
| Luke Allain | PA | The Hill School | 2018 | LHP | Bucknell |
| Jeff Allen | PA | Mechanicsburg Area | 2015 | RHP | Indiana University (PA) |
| Chris Alleyne | PA | Springside Chestnut Hill | 2017 | SS | Maryland |
| Craig Alleyne | PA | Springside Chestnut Hill | 2014 | OF | Fairleigh Dickinson |
| Erick Almonte | PA | Scotland Campus Sports | 2022 | SS | SC - FL(Manatee-Sarasota) |
| Ray Altmeyer | PA | Bethel Park | 2023 | OF | Mercyhurst |
| Chris Altopiedi | PA | Archbishop John Carroll | 2016 | LHP | La Salle |
| Donald Alway | PA | Seneca Valley | 2018 | RHP | Slippery Rock |
| Evan Alwine | PA | Altoona Area | 2023 | RHP | Florida International |
| Jon Aman | PA | Friends Central | 2022 | OF | Widener University |
| Coty Amant | PA | Delaware Valley | 2015 | 1B | Lehigh Carbon CC |
| Preston Amato | PA | Southern Lehigh | 2015 | SS | DeSales University |
| Quin Ambeault | PA | Greencastle-Antrim | 2016 | C | Hagerstown CC |
| Jake Ambrosio | PA | Owen J. Roberts | 2023 | C | Lock Haven University |
| Tyler Amedure | PA | West Allegheny | 2015 | SS | Alderson Broaddus |
| Nick Amey | PA | Emmaus | 2017 | OF | Immaculata University |
| Nick Amicon | PA | Downingtown East | 2015 | SS | University of the Science |
| Sam Amodeo | PA | Pittsburgh Central Catholic | 2022 | RHP | John Carroll |
| Niko Amory | PA | Southern Lehigh | 2018 | C | Marist |
| Nicolas Ampietro | PA | Salisbury Township | 2013 | RHP | Moravian College |
| Mikey Amrhein | PA | Neshaminy | 2023 | OF | Mercer County CC |
| Mike Anastasia | PA | Central Bucks South | 2015 | OF | New Jersey Tech |
| JT Anderosky | PA | Central Bucks South | 2022 | OF | DeSales University |
| Justin Anderosky | PA | Central Bucks South | 2017 | RHP | Chestnut Hill College |
| Brandin Anderson | PA | DuBois Central Catholic | 2022 | RHP | Youngstown State |
| Mike Anderson | PA | Bonner-Prendergast | 2022 | 1B | Rhode Island |
| Connor Anderson | PA | Central Dauphin | 2014 | SS | Harford CC |
| Michael Anderson | PA | Bonner-Prendergast | 2022 | 1B | Rhode Island |
| Jack Anderson | PA | Mars Area | 2019 | C | SC - FL(Manatee-Sarasota) |
| Colby Anderson | PA | Butler Area | 2019 | LHP | Slippery Rock |
| Jack Anderson | PA | Mars Area | 2018 | C | Northwestern |
| Mark Anderson | PA | Conestoga | 2016 | LHP | Lafayette |
| Trevor Andreson | PA | Owen J. Roberts | 2014 | 2B | Scranton |
| Chris Andrews | PA | Southern Lehigh | 2020 | OF | Monmouth |
| Alec Andrews | PA | Friends' Central | 2017 | RHP | Muhlenberg |
| Justin Andrews | PA | Neshaminy | 2013 | OF | Monmouth |
| Logan Andreyko | PA | North Allegheny | 2021 | OF | Case Western |
| Shane Anhalt | PA | Council Rock North | 2022 | 1B | DeSales University |
| Jake Ansell | PA | Connellsville | 2018 | RHP | Pittsburgh-Johnstown |
| Mike Anthony | PA | Phoenixville Area | 2015 | RHP | La Salle |
| Brett Antolick | PA | Hazleton Area | 2023 | RHP | Texas A&M |
| Ryan Apaliski | PA | Hampton Area | 2023 | LHP | James Madison |
| Jonas Aponick | PA | Hazleton Area | 2024 | RHP | George Washington |
| Kyle Arganbright | PA | Hempfield | 2015 | RHP | Northampton CC |
| Jordi Arias | PA | Hazleton Area | 2016 | SS | Harford CC |
| Gianni Arici | PA | St. Joseph's Prep | 2018 | SS | Quinnipiac |
| Jake Arienzo | PA | Slippery Rock | 2015 | LHP | Clarion University |
| Lucas Arington | PA | Hopewell | 2023 | 1B | Tiffin University |
| Manny Ariza | PA | Perkiomen School | 2020 | LHP | SUNY-Old Westbury |
| Dante Armanini | PA | DuBois Central Catholic | 2021 | OF | Saint Vincent |
| Dane Armson | PA | Loyalsock Township | 2020 | RHP | Richmond |
| Tyler Armstrong | PA | Pine-Richland | 2022 | 1B | East Georgia State JC |
| Andrew Armstrong | PA | Harry S. Truman | 2023 | 1B | Bloomsburg University |
