Offseason
- October 20, 1965: Ken Boyer was traded by the Cardinals to the New York Mets for Charley Smith and Al Jackson.
- October 27, 1965: Dick Groat, Bob Uecker and Bill White were traded by the Cardinals to the Philadelphia Phillies for Pat Corrales, Art Mahaffey, and Alex Johnson.
- November 29, 1965: Nate Colbert was drafted from the Cardinals by the Houston Astros in the 1965 rule 5 draft.
- November 29, 1965: 1965 first-year draft
- Jimy Williams was drafted by the Cardinals from the Boston Red Sox.
- Willie Montañez was drafted from the Cardinals by the California Angels.
Read more about this topic: 1966 St. Louis Cardinals Season