Wow, check out some of these killer trades.
- March 31, 2018. The St. Louis Cardinals traded Josh Lucas to the Oakland Athletics for Casey Meisner (minors).
- December 14, 2017. The St. Louis Cardinals traded Stephen Piscotty to the Oakland Athletics for Max Schrock (minors) and Yairo Munoz.
- August 8, 2014. The Oakland Athletics purchased Angel Castro from the St. Louis Cardinals.
- April 4, 2012. The Oakland Athletics sent Cedric Hunter to the St. Louis Cardinals as part of a conditional deal.
- July 24, 2009. The Oakland Athletics traded Matt Holliday to the St. Louis Cardinals for Clayton Mortensen, Shane Peterson and Brett Wallace.
- December 18, 2004. The St. Louis Cardinals traded Daric Barton, Kiko Calero and Dan Haren to the Oakland Athletics for Mark Mulder.
- July 31, 1997. The St. Louis Cardinals traded Eric Ludwick, T.J. Mathews and Blake Stein to the Oakland Athletics for Mark McGwire.
- February 13, 1996. The St. Louis Cardinals traded Steve Montgomery to the Oakland Athletics for Dennis Eckersley.
- January 9, 1996. The Oakland Athletics traded Todd Stottlemyre to the St. Louis Cardinals for Bret Wagner (minors), Allen Battle, Carl Dale and Jay Witasick.
- August 29, 1990. The Oakland Athletics traded Daryl Green (minors), Felix Jose and Stan Royer to the St. Louis Cardinals for Willie McGee.
- December 10, 1985. The St. Louis Cardinals traded Joaquin Andujar to the Oakland Athletics for Tim Conroy and Mike Heath.
- September 2, 1983. The Oakland Athletics traded Steve Baker to the St. Louis Cardinals for players to be named later. The St. Louis Cardinals sent Tom Dozier (September 16, 1983) and Jim Strichek (minors) (September 16, 1983) to the Oakland Athletics to complete the trade.
- August 12, 1977. The Oakland Athletics traded Randy Scarbery to the St. Louis Cardinals for Steve Dunning.
- March 26, 1977. The St. Louis Cardinals purchased Tommy Sandt from the Oakland Athletics.
- September 14, 1976. The Oakland Athletics purchased Ron Fairly from the St. Louis Cardinals.
- October 28, 1975. The St. Louis Cardinals traded Larry Lintz to the Oakland Athletics for Charlie Chant.
- May 18, 1975. The St. Louis Cardinals traded Ted Martinez to the Oakland Athletics for a player to be named later and Steve Staniland (minors). The Oakland Athletics sent Mike Barlow (May 23, 1975) to the St. Louis Cardinals to complete the trade.
- December 2, 1974. The St. Louis Cardinals purchased Bill Parsons from the Oakland Athletics.
- March 26, 1974. The Oakland Athletics purchased Larry Haney from the St. Louis Cardinals.
- January 9, 1974. The St. Louis Cardinals purchased Jay Johnstone from the Oakland Athletics.
- September 1, 1973. The St. Louis Cardinals purchased Larry Haney from the Oakland Athletics.
- August 30, 1972. The St. Louis Cardinals traded Dal Maxvill to the Oakland Athletics for a player to be named later and Joe Lindsey (minors). The Oakland Athletics sent Gene Dusan (minors) (October 27, 1972) to the St. Louis Cardinals to complete the trade.
- August 27, 1972. The St. Louis Cardinals traded Matty Alou to the Oakland Athletics for Stephen Easton (minors) and Bill Voss.
- June 7, 1972. The Oakland Athletics sent Diego Segui to the St. Louis Cardinals as part of a conditional deal.
- May 28, 1972. The St. Louis Cardinals traded Marty Martinez to the Oakland Athletics for Brant Alyea. Brant Alyea returned to original team on July 23, 1972.
- May 15, 1972. The St. Louis Cardinals traded Don Shaw to the Oakland Athletics for Dwain Anderson.
- October 21, 1971. The St. Louis Cardinals returned Daryl Patterson to the Oakland Athletics following previous purchase.
- July 20, 1971. The Oakland Athletics traded Dennis Higgins to the St. Louis Cardinals for Gaylen Pitts.
- June 25, 1971. The St. Louis Cardinals purchased Daryl Patterson from the Oakland Athletics.
- December 5, 1969. The Oakland Athletics purchased Mudcat Grant from the St. Louis Cardinals.
- July 12, 1969. The St. Louis Cardinals traded Bob Johnson to the Oakland Athletics for Joe Nossek.
- October, 1965. The St. Louis Cardinals purchased Moe Drabowsky from the Kansas City Athletics. (Date given is approximate. Exact date is uncertain.)
- October 11, 1961. The St. Louis Cardinals purchased Ozzie Virgil from the Kansas City Athletics.
- July 21, 1961. The Kansas City Athletics purchased Mickey McDermott from the St. Louis Cardinals.
- June 1, 1954. The St. Louis Cardinals returned Carl Scheib to the Philadelphia Athletics as part of a conditional deal.
- May 7, 1954. The Philadelphia Athletics sent Carl Scheib to the St. Louis Cardinals as part of a conditional deal.
- September 30, 1946. The St. Louis Cardinals traded Eddie Joost to the Philadelphia Athletics for a player to be named later, Vern Benson, Jake Caulfield and Russ Derry. The Philadelphia Athletics sent $30,000 (March 24, 1947) to the St. Louis Cardinals to complete the trade.
- May 14, 1938. The St. Louis Cardinals traded Dick Siebert to the Philadelphia Athletics for Paul Easterling, Gene Hasson and George Turbeville.