Offseason
- October 28, 1998: Bruce Aven was selected off waivers by the Florida Marlins from the Cleveland Indians.
- December 14, 1998: Edgar Rentería was traded by the Florida Marlins to the St. Louis Cardinals for Armando Almanza, Braden Looper, and Pablo Ozuna.
- December 23, 1998: Gregg Zaun was sent to the Texas Rangers by the Florida Marlins as part of a conditional deal.
Read more about this topic: 1999 Florida Marlins Season