Offseason
- October 16, 1956: Hank Sauer was released by the Cardinals.
- November 27, 1956: Charlie Peete, 27, was killed in a plane crash, along with his wife and three children, while flying to Venezuela to play Winter League ball. He was projected to be the Cardinals' starting center fielder in 1957.
- December 3, 1956: Bob Smith was drafted by the Cardinals from the Boston Red Sox in the 1956 rule 5 draft.
- December 11, 1956: Tom Poholsky, Jackie Collum, Ray Katt, and Wally Lammers (minors) were traded by the Cardinals to the Chicago Cubs for Eddie Miksis, Jim Davis, Sam Jones, and Hobie Landrith.
- February 26, 1957: Whitey Lockman was traded by the Cardinals to the New York Giants for Hoyt Wilhelm.
- Prior to 1957 season: Cal Browning was signed as an amateur free agent by the Cardinals.
Read more about this topic: 1957 St. Louis Cardinals Season