- August 2, 2022. The Cincinnati Reds purchased Austin Romine from the St. Louis Cardinals
- April 21, 2006: The St. Louis Cardinals purchased Timo Perez from the Cincinnati Reds.
- July 12, 2002: The Cincinnati Reds purchased Gerald Williams from the St. Louis Cardinals.
- November 10, 1997: The St. Louis Cardinals traded Dmitri Young to the Cincinnati Reds for Jeff Brantley.
- December 4, 1995: As part of a 3-team trade: The Cincinnati Reds sent Mike Remlinger to the Kansas City Royals. The Cincinnati Reds sent Luis Ordaz to the St. Louis Cardinals. The Kansas City Royals sent Miguel Mejia to the St. Louis Cardinals. The St. Louis Cardinals sent Andre King (minors) to the Cincinnati Reds.
- August 31, 1987: The St. Louis Cardinals traded Pat Perry to the Cincinnati Reds for a player to be named later. TheCincinnati Reds sent Scott Terry (September 3, 1987) to the St. Louis Cardinals to complete the trade.
- August 29, 1985: The St. Louis Cardinals traded Mark Jackson (minors) to the Cincinnati Reds for Cesar Cedeno.
- September 9, 1984: The Cincinnati Reds traded Paul Householder to the St. Louis Cardinals for John Stuper.
- March 31, 1983: The St. Louis Cardinals traded Kelly Paris to the Cincinnati Reds for Jim Strichek (minors).
- April 1, 1982: The St. Louis Cardinals traded Bob Shirley to the Cincinnati Reds for Oscar Brito (minors) and Jeff Lahti.
- September 10, 1981: The St. Louis Cardinals traded Joe Edelen and Neil Fiala to the Cincinnati Reds for Doug Bair.
- June 15, 1977: The St. Louis Cardinals traded Doug Capilla to the Cincinnati Reds for Rawly Eastwick.
- March 29, 1977: The St. Louis Cardinals traded Mike Caldwell to the Cincinnati Reds for Pat Darcy.
- March 28, 1977: The St. Louis Cardinals traded Bill Caudill to the Cincinnati Reds for Joel Youngblood.
- July 27, 1973: The St. Louis Cardinals traded Gene Dusan (minors) and Ed Crosby to the Cincinnati Reds for a player to be named later and Ed Sprague. The Cincinnati Reds sent Roe Skidmore (September 30, 1973) to the St. Louis Cardinals to complete the trade.
- November 28, 1972: The Cincinnati Reds traded Pat Jacquez to the St. Louis Cardinals for Bill Voss.
- May 19, 1972: The St. Louis Cardinals traded Joe Hague to the Cincinnati Reds for Bernie Carbo.
- March 24, 1972: The St. Louis Cardinals traded Julian Javier to the Cincinnati Reds for Tony Cloninger.
- December 14, 1971: The Cincinnati Reds traded Danny Godby to the St. Louis Cardinals for Carroll Sembera.
- November 5, 1969: The Cincinnati Reds traded George Culver to the St. Louis Cardinals for Ray Washburn.
- June 14, 1969: The St. Louis Cardinals traded Dennis Ribant to the Cincinnati Reds for Aurelio Monteagudo.
- October 11, 1968: The Cincinnati Reds traded Vada Pinson to the St. Louis Cardinals for Wayne Granger and Bobby Tolan.
- February 8, 1968: The St. Louis Cardinals traded Pat Corrales and Jimy Williams to the Cincinnati Reds for Johnny Edwards.
- January 11, 1968: The St. Louis Cardinals traded Alex Johnson to the Cincinnati Reds for Dick Simpson.
- June, 1965: The Cincinnati Reds purchased Dick Egan from the St. Louis Cardinals.
- December 14, 1964: The Cincinnati Reds traded Bob Purkey to the St. Louis Cardinals for Roger Craig and Charlie James.
- June 13, 1964: The St. Louis Cardinals traded Jim Saul (minors) and cash to the Cincinnati Reds for Bob Skinner.
- July 29, 1960: The St. Louis Cardinals purchased Bob Grim from the Cincinnati Reds.
- April, 1960: The Cincinnati Reds purchased Howie Nunn from the St. Louis Cardinals.
- June 8, 1959: The Cincinnati Redlegs traded Hal Jeffcoat to the St. Louis Cardinals for Jim Brosnan.
- October 3, 1958: The Cincinnati Redlegs traded George Crowe, Alex Grammas and Alex Kellner to the St. Louis Cardinals for Del Ennis, Eddie Kasko and Bob Mabe.
- December 5, 1957: The St. Louis Cardinals traded Marty Kutyna, Willard Schmidt and Ted Wieand to the Cincinnati Redlegs for Curt Flood and Joe Taylor.
- May 16, 1956: The St. Louis Cardinals traded Joe Frazier and Alex Grammas to the Cincinnati Redlegs for Chuck Harmon.
- May 1, 1956: The St. Louis Cardinals traded Paul LaPalme to the Cincinnati Redlegs for Milt Smith.
- January 31, 1956: The Cincinnati Redlegs traded Jackie Collum to the St. Louis Cardinals for Brooks Lawrence andSonny Senerchia.
- December 8, 1954: The St. Louis Cardinals traded Ray Jablonski and Gerry Staley to the Cincinnati Redlegs for Frank Smith.
- December 2, 1953: The St. Louis Cardinals traded Jack Crimian and $100,000 to the Cincinnati Reds for Alex Grammas.
- May 23, 1953: The St. Louis Cardinals traded Jackie Collum to the Cincinnati Reds for Eddie Erautt.
- May 13, 1952: The St. Louis Cardinals traded Eddie Kazak and Wally Westlake to the Cincinnati Reds for Dick Sislerand Virgil Stallcup.
- September 7, 1950: The St. Louis Cardinals purchased Peanuts Lowrey from the Cincinnati Reds.
- December 14, 1949: The St. Louis Cardinals traded Lou Klein and Ron Northey to the Cincinnati Reds for Harry Walker.
- August 9, 1949: The St. Louis Cardinals traded Ed Blake to the Cincinnati Reds for Mike Schultz.
- July 26, 1948: The St. Louis Cardinals traded Ken Burkhart to the Cincinnati Reds for Babe Young.
- June 15, 1944: The Cincinnati Reds purchased Harry Gumbert from the St. Louis Cardinals.
- September 15, 1942: The Cincinnati Reds purchased Ray Mueller from the St. Louis Cardinals.
- May 6, 1942: The St. Louis Cardinals traded Clyde Shoun and cash to the Cincinnati Reds for Whitey Moore.
- May 6, 1942: The Cincinnati Reds traded Jim Gleeson to the St. Louis Cardinals for Max Marshall.
- September 9, 1941: The Cincinnati Reds purchased Bert Haas from the St. Louis Cardinals.
- June 21, 1941: The St. Louis Cardinals purchased Jimmy Ripple from the Cincinnati Reds.
- May 14, 1941: The St. Louis Cardinals purchased Pep Young from the Cincinnati Reds.
- May 14, 1941: The Cincinnati Reds purchased Ernie Koy from the St. Louis Cardinals.
- December 16, 1940: The Cincinnati Reds purchased Tot Pressnell from the St. Louis Cardinals.
- December 8, 1938: The St. Louis Cardinals traded Frenchy Bordagaray to the Cincinnati Reds for Dusty Cooke.
- December 2, 1936: The Cincinnati Reds purchased Spud Davis from the St. Louis Cardinals.
- August 6, 1936: The St. Louis Cardinals purchased Si Johnson from the Cincinnati Reds.
- August 2, 1936: The Cincinnati Reds purchased Phil Weintraub from the St. Louis Cardinals.
- August 2, 1936: The Cincinnati Reds purchased Jack Rothrock from the St. Louis Cardinals.
- June 19, 1936: The St. Louis Cardinals purchased Flint Rhem from the Cincinnati Reds.
- May 31, 1936: The St. Louis Cardinals purchased Tony Freitas from the Cincinnati Reds.
- May 31, 1936: The Cincinnati Reds purchased Bill Hallahan from the St. Louis Cardinals.
- April 15, 1935: The Cincinnati Reds returned Johnny Mize to the St. Louis Cardinals following previous purchase.
- December 13, 1934: The Cincinnati Reds purchased Johnny Mize from the St. Louis Cardinals.
- November 3, 1934: The Cincinnati Reds purchased Ival Goodman from the St. Louis Cardinals for $25,000.
- November 3, 1934: The Cincinnati Reds purchased Lew Riggs from the St. Louis Cardinals for $30,000.
- January 11, 1934: The St. Louis Cardinals traded Syl Johnson and Bob O’Farrell to the Cincinnati Reds for Glenn Spencer.
- May 7, 1933: The St. Louis Cardinals traded Sparky Adams, Paul Derringer and Allyn Stout to the Cincinnati Reds forLeo Durocher, Dutch Henry and Jack Ogden.
- January 20, 1933: The St. Louis Cardinals purchased Wally Gilbert from the Cincinnati Reds.
- January 3, 1933: The St. Louis Cardinals purchased Lance Richbourg from the Cincinnati Reds.
- December 17, 1932: The St. Louis Cardinals traded Jim Bottomley to the Cincinnati Reds for Ownie Carroll and Estel Crabtree.
- June 5, 1932: The Cincinnati Reds purchased Harvey Hendrick from the St. Louis Cardinals.
- June 5, 1932: The St. Louis Cardinals purchased Mickey Heath from the Cincinnati Reds.
- May 9, 1932: The Cincinnati Reds purchased Benny Frey from the St. Louis Cardinals.
- April 11, 1932: The Cincinnati Reds traded Benny Frey, Harvey Hendrick and cash to the St. Louis Cardinals for Chick Hafey.
- January 26, 1932: The St. Louis Cardinals purchased Hod Ford from the Cincinnati Reds.
- December 2, 1931: The Cincinnati Reds traded Nick Cullop and cash to the St. Louis Cardinals for Andy High.
- December, 1931: The Cincinnati Reds purchased Wally Roettger from the St. Louis Cardinals.
- June 15, 1931: The St. Louis Cardinals traded Taylor Douthit to the Cincinnati Reds for Wally Roettger.
- May 4, 1925: The St. Louis Cardinals purchased Hi Myers from the Cincinnati Reds.
- April 22, 1925: The Cincinnati Reds purchased Hi Myers from the St. Louis Cardinals.
- July 13, 1923: The Cincinnati Reds purchased Les Mann from the St. Louis Cardinals. (Date given is approximate. Exact date is uncertain.)
- July 24, 1915: The St. Louis Cardinals purchased Red Ames from the Cincinnati Reds.
- April 8, 1915: The St. Louis Cardinals traded Ivey Wingo to the Cincinnati Reds for Mike Gonzalez.
- January 1, 1913: The St. Louis Cardinals purchased Larry McLean from the Cincinnati Reds.
- February 3, 1910: The St. Louis Cardinals traded Fred Beebe and Alan Storke to the Cincinnati Reds for Frank Corridon, Miller Huggins and Rebel Oakes.
- August 22, 1909: The St. Louis Cardinals traded Chappy Charles to the Cincinnati Reds for Mike Mowrey.
- May 2, 1909: The St. Louis Cardinals purchased Rudy Hulswitt from the Cincinnati Reds.
- Before 1909 Season: The Cincinnati Reds purchased Art Hoelskoetter from the St. Louis Cardinals.
- December 12, 1908: The St. Louis Cardinals traded Art Fromme and Ed Karger to the Cincinnati Reds for Admiral Schlei.
- July 25, 1906: The St. Louis Cardinals traded Homer Smoot to the Cincinnati Reds for Shad Barry.
- May 7, 1906: The St. Louis Cardinals traded Oscar Stanage to the Cincinnati Reds for Carl Druhot.
- January 25, 1905: The St. Louis Cardinals purchased Win Kellum from the Cincinnati Reds.
- February 11, 1904: The St. Louis Cardinals purchased Jake Beckley from the Cincinnati Reds.
- July 21, 1902: The St. Louis Cardinals purchased Clarence Currie from the Cincinnati Reds.