The Cardinals went 75-86 during the season and finished 4th in the National League Central division, 21½ games behind the Houston Astros.
- November 19, 1998: Eric Davis was signed as a Free Agent with the St. Louis Cardinals.
November 19, 1998: Ricky Bottalico was traded by the Philadelphia Phillies with Garrett Stephenson to the St. Louis Cardinals for Jeff Brantley, Ron Gant, and Cliff Politte.
December 7, 1998: Willie McGee was signed as a Free Agent with the St. Louis Cardinals.
December 14, 1998: Edgar Rentería was traded by the Florida Marlins to the St. Louis Cardinals for Armando Almanza, Braden Looper, and Pablo Ozuna.
January 15, 1999: Mike Mohler was signed as a Free Agent with the St. Louis Cardinals.
On April 23, 1999, Fernando Tatís hit two grand slams in the third inning, both off Chan Ho Park.
In 1999, Mark McGwire drove in a league-leading 147 runs while only having 145 hits, the highest RBI-per-hit tally in baseball history
May 15, 1999: Heathcliff Slocumb was signed as a Free Agent with the St. Louis Cardinals.
June 2, 1999: Albert Pujols was drafted by the St. Louis Cardinals in the 13th round of the 1999 amateur draft. Player signed August 17, 1999