- New York Mets selected Jim Hickman in free agent draft on October 10, 1961.
- New York Mets selected Craig Anderson in free agent draft on October 10, 1961.
- New York Mets selected Chris Cannizzaro in free agent draft on October 10, 1961.
- New York Mets traded Jacke Davis to the St. Louis Cardinals for Duke Carmel on July 29, 1963.
- New York Mets traded Ken MacKenzie to the St. Louis Cardinals for Ed Bauta on August 5, 1963.
- New York Mets traded Roger Craig to the St. Louis Cardinals for George Altman and Bill Wakefield on November 4, 1963.
- New York Mets traded Elio Chacon and Tracy Stallard to the St. Louis Cardinals for Johnny Lewis and Gordie Richardson on December 8, 1964.
- New York Mets traded Al Jackson and Charley Smith to the St. Louis Cardinals for Ken Boyer on October 20, 1965.
- New York Mets traded Eddie Bressoud and Danny Napoleon to the St. Louis Cardinals for Jerry Buchek, Art Mahaffey and Tony Martinez on April 1, 1967.
- New York Mets traded Jack Lamabe to the St. Louis Cardinals for Al Jackson on July 16, 1967.
- New York Mets traded Art Shamsky, Rich Folkers, Jim Bibby and Charlie Hudson to the St. Louis Cardinals for Jim Beauchamp, Harry Parker, Chuck Taylor and Tom Coulter on October 18, 1971.
- New York Mets traded Ray Sadecki and Tommy Moore to the St. Louis Cardinals for Joe Torre on October 13, 1974.
- New York Mets traded Ted Martinez to the St. Louis Cardinals for Mike Vail and Jack Heidemann on December 11, 1974.
- New York Mets sold Harry Parker to the St. Louis Cardinals on August 4, 1975.
- New York Mets traded Leon Brown and Brock Pemberton to the St. Louis Cardinals for Ed Kurpiel on December 9, 1976.
- New York Mets traded Benny Ayala to the St. Louis Cardinals for Doug Clarey on March 30, 1977.
- New York Mets traded Mike Phillips to the St. Louis Cardinals for Joel Youngblood on June 15, 1977.
- New York Mets purchased Butch Metzger from the St. Louis Cardinals on April 5, 1978.
- New York Mets traded Paul Siebert to the St. Louis Cardinals for Bob Coluccio on October 2, 1978.
- New York Mets traded Tom Grieve and Kim Seaman to the St. Louis Cardinals for Pete Falcone on December 5, 1978.
- New York Mets traded Neil Allen and Rick Ownbey to the St. Louis Cardinals for Keith Hernandez on June 15, 1983.
- New York Mets sold Gary Rajsich to the St. Louis Cardinals on April 5, 1984.
- New York Mets traded Jose Oquendo and Mark Jason Davis to the St. Louis Cardinals for Angel Salazar and John Young on April 2, 1985.
- New York Mets selected Clint Hurdle in free agent draft on December 10, 1985.
- New York Mets signed free agent Vince Coleman of the St. Louis Cardinals on December 5, 1990.
- New York Mets traded Chuck Carr to the St. Louis Cardinals for Clyde Keller on December 13, 1991.
- New York Mets traded Erik Hiljus, Yudith Ozario and Eric Ludwick to the St. Louis Cardinals for Bernard Gilkey on January 22, 1996.
- New York Mets traded Juan Acevedo to the St. Louis Cardinals for Rigo Beltran on March 29, 1998.
- New York Mets traded Shawn Gilbert to the St. Louis Cardinals for Wayne Kirby on June 10, 1998.
- New York Mets traded Craig Paquette to the St. Louis Cardinals for Shawon Dunston on July 31, 1999.
- St. Louis Cardinals signed Shawon Dunston of the New York Mets as a free agent on February 3, 2000.
- New York Mets traded Jesse Orosco to the St. Louis Cardinals for Joe McEwing on March 18, 2000.
- New York Mets claimed Esix Snead on waivers from the St. Louis Cardinals on November 20, 2001.
- New York Mets traded Roger Cedeno to the St. Louis Cardinals for Wilson Delgado and Chris Widger on April 3, 2004.
- St. Louis Cardinals signed Prentice Redman of the New York Mets as a free agent on November 8, 2005.
- St. Louis Cardinals signed Braden Looper of the New York Mets as a free agent on December 15, 2005.
- St. Louis Cardinals signed Brian Daubach of the New York Mets as a free agent on December 20, 2005.
- New York Mets signed free agent Jorge Sosa of the St. Louis Cardinals on January 16, 2007.
- St. Louis Cardinals signed Raul Valdes of the New York Mets as a free agent on November 23, 2010.
- St. Louis Cardinals signed Rob Johnson of the New York Mets as a free agent on November 13, 2012.
- St. Louis Cardinals signed Ronny Cedeno of the New York Mets as a free agent on January 28, 2013.
- New York Mets selected Sean Gilmartin in free agent draft on June 11, 2017.
- St. Louis Cardinals signed Chris Beck of the New York Mets as a free agent on November 22, 2018.
- New York Mets signed free agent Chasen Shreve of the St. Louis Cardinals on December 3, 2019.
- New York Mets signed free agent Michael Wacha of the St. Louis Cardinals on December 13, 2019.
- New York Mets sold Ali Sanchez to the St. Louis Cardinals on February 12, 2021.
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