| 28 January 2019 | Agreed to terms with INFs Sean Kazmar, Luis Marte, Andres Blanco and Pedro Florimon; and OFs Ryan LaMarre and Rafael Ortega on minor league contracts. |
| 22 January 2019 | Agreed to terms with OF Nick Markakis on a one-year contract. |
| 14 January 2019 | Named Perry Minasian senior vice president of baseball operations and assistant general manager; Alex Tamin assistant general manager, major league operations; Dixie Keller director, baseball administration; Garrett Wilson manager, baseball systems; Noah Woodward manager, major league operations; Elizabeth Teran executive assistant to the executive vice president and general manager; Matt Grabowski assistant director, amateur scouting operations; Ron Knight assistant director, minor league operations; Jonathan Schuerholz assistant director, professional scouting; and A.J. Scola assistant director, minor league personnel. |
| 11 January 2019 | Agreed to terms with INF Charlie Culberson, OF Adam Duvall, LHP Sam Freeman and RHPs Mike Foltynewicz, Kevin Gausman, Arodys Vizcaino and Dan Winkler on one-year contracts. Named Dana Brown vice president/scouting. |
| 2 January 2019 | Named Mike Maroth pitching coach, Bobby Magallanes hitting coach and Einar Diaz coach of Gwinnett (IL); Alfredo Amezaga coach of Mississippi (SL); Barrett Kleinknect manager, Dan Meyer pitching coach and Doug DeVore hitting coach of Florida (FSL); Matt Tuiasosopo manager of Rome (SAL); Anthony Nunez manager, Danny Santiesteban hitting coach, Connor Narron coach and Koji Kanemura trainer of Danville (Appalachian); Barbaro Garbey second hitting coach, Angel Flores coach and Austin Smith trainer of the GCL Braves; and Doug Mansolino minor league field coordinator. |
