Offseason
- December 8, 1939: Al Todd was traded by the Dodgers to the Chicago Cubs for Gus Mancuso and Newt Kimball.
- December 26, 1939: Boze Berger was purchased by the Dodgers from the Boston Red Sox.
- February 6, 1940: Herman Franks was purchased by the Dodgers from the St. Louis Cardinals.
- February 12, 1940: Joe Vosmik was purchased by the Dodgers from the Boston Red Sox.
- Prior to 1940 season: Wally Westlake was signed as an amateur free agent by the Dodgers.
Read more about this topic: 1940 Brooklyn Dodgers Season