There are 36 former NCAA Division I players on the roster of the 2019 MLB League Championship Series. There are 32 different schools represented.
LSU leads with three players: Alex Bregman and Will Harris of the Houston Astros, as well as DJ LeMahieu of the New York Yankees. Old Dominion (Daniel Hudson of the Washington Nationals, Justin Verlander of the Houston Astros) and Virginia (Sean Doolittle and Ryan Zimmerman of the Washington Nationals) both have two.
The St. Louis Cardinals and the Washington Nationals both have 11 former Division I players on their rosters. The New York Yankees have eight and the Houston Astros have six.
| Cal State Fullerton | Kurt | Suzuki | C | Washington Nationals |
| College of Charleston | Brett | Gardner | OF | New York Yankees |
| Connecticut | George | Springer | OF | Houston Astros |
| Elon | John | Brebbia | RHP | St. Louis Cardinals |
| Florida | Harrison | Bader | OF | St. Louis Cardinals |
| Fresno State | Aaron | Judge | OF | New York Yankees |
| Georgia Tech | Matt | Wieters | C | St. Louis Cardinals |
| Hawaii | Kolten | Wong | 2B | St. Louis Cardinals |
| Illinois State | Paul | DeJong | SS | St. Louis Cardinals |
| Kentucky | James | Paxton | LHP | New York Yankees |
| Louisville | Chad | Green | RHP | New York Yankees |
| LSU | Alex | Bregman | 3B | Houston Astros |
| LSU | Will | Harris | RHP | Houston Astros |
| LSU | DJ | LeMahieu | 2B | New York Yankees |
| Miami (Ohio) | Adam | Eaton | OF | Washington Nationals |
| Mississippi State | Dakota | Hudson | RHP | St. Louis Cardinals |
| Missouri | Max | Scherzer | RHP | Washington Nationals |
| NC State | Trea | Turner | SS | Washington Nationals |
| North Carolina | Andrew | Miller | LHP | St. Louis Cardinals |
| Northeastern | Adam | Ottavino | RHP | New York Yankees |
| Northwestern | J.A. | Happ | LHP | New York Yankees |
| Oklahoma State | Tyler | Lyons | LHP | New York Yankees |
| Old Dominion | Daniel | Hudson | RHP | Washington Nationals |
| Old Dominion | Justin | Verlander | RHP | Houston Astros |
| Rice | Anthony | Rendon | 3B | Washington Nationals |
| San Diego State | Stephen | Strasburg | RHP | Washington Nationals |
| South Carolina | Tyler | Webb | LHP | St. Louis Cardinals |
| Southern Miss | Brian | Dozier | 2B | Washington Nationals |
| Stanford | Tommy | Edman | SS | St. Louis Cardinals |
| TCU | Matt | Carpenter | 3B | St. Louis Cardinals |
| Texas State | Paul | Goldschmidt | 1B | St. Louis Cardinals |
| UCLA | Gerrit | Cole | RHP | Houston Astros |
| Virginia | Sean | Doolittle | LHP | Washington Nationals |
| Virginia | Ryan | Zimmerman | 1B | Washington Nationals |
| Washington | Austin | Voth | RHP | Washington Nationals |
| Wright State | Joe | Smith | RHP | Houston Astros |