Offseason
- December 13, 1979: Greg Gross was signed as a free agent by the Philadelphia Phillies.
- December 20, 1979: Jerry Willard was signed as an amateur free agent by the Phillies.
- March 30, 1980: Dave Rader was traded by the Phillies to the Boston Red Sox for a player to be named later and cash. The Red Sox completed the deal by sending Stan Papi to the Phillies on May 12.
Read more about this topic: 1980 Philadelphia Phillies Season