Transactions listed are from November 1 of previous year to April 1 of the following year.
The St. Louis Cardinals purchased Les Mann from the Boston Braves.
San Francisco (PCL) traded Bert Cole to the Detroit Tigers for Babe Ellison.
The Philadelphia Phillies traded Eppa Rixey to the Cincinnati Reds for Greasy Neale and Jimmy Ring.
The Cincinnati Reds selected Dode Paskert off waivers from the Chicago Cubs.
The New York Yankees traded Del Pratt, Muddy Ruel, Hank Thormahlen and Sammy Vick to the Boston Red Sox for Harry Harper, Waite Hoyt, Mike McNally and Wally Schang.
The Cincinnati Reds traded Dutch Ruether to the Brooklyn Robins for Rube Marquard.
The Washington Senators traded Braggo Roth to the New York Yankees for Duffy Lewis and George Mogridge.
The Boston Braves traded a player to be named later and cash to Beaumont (Texas) for a player to be named later and Al Nixon. The Boston Braves sent Pep Ripper (minors) (May 12, 1921) to Beaumont (Texas) to complete the trade.
The Detroit Tigers signed Heinie Manush as a free agent.
The Pittsburgh Pirates traded Walter Barbare, Fred Nicholson, Billy Southworth and $15,000 to the Boston Braves for Rabbit Maranville.
The Chicago Cubs released Claude Hendrix.
The Chicago White Sox traded Shano Collins and Nemo Leibold to the Boston Red Sox for Harry Hooper.
Columbus (American Association) purchased Art Wilson from the Boston Braves.
Rochester (International) purchased Maurice Archdeacon from the Boston Braves.
The Philadelphia Phillies selected Cliff Lee off waivers from the Pittsburgh Pirates.
The Brooklyn Robins selected Sweetbreads Bailey off waivers from the Chicago Cubs.
The Chicago Cubs purchased John Sullivan from the Boston Braves.
The Boston Red Sox selected Allen Sothoron off waivers from the St. Louis Browns.
The Washington Senators traded Frank Ellerbe to the St. Louis Browns for Earl Smith.
The Detroit Tigers purchased Pol Perritt from the New York Giants.
The Cleveland Indians selected Allen Sothoron off waivers from the Boston Red Sox. (Date given is approximate. Exact date is uncertain.)
The Cincinnati Reds selected Greasy Neale off waivers from the Philadelphia Phillies.
The St. Louis Cardinals traded Hal Janvrin and Ferdie Schupp to the Brooklyn Robins for Jeff Pfeffer.
The Philadelphia Phillies purchased Jimmy Smith from the Cincinnati Reds.
The Pittsburgh Pirates selected Tony Brottem off waivers from the Washington Senators.
The Pittsburgh Pirates traded Elmer Ponder to the Chicago Cubs for Dave Robertson.
The Philadelphia Phillies traded Johnny Rawlings and Casey Stengel to the New York Giants for Lee King, Goldie Rapp and Lance Richbourg.
The Philadelphia Phillies selected Ed Konetchy off waivers from the Brooklyn Robins.
The Philadelphia Phillies traded Red Causey to the New York Giants for John Monroe and Jesse Winters.
The Chicago White Sox purchased Elmer Leifer from Moose Jaw (Western Canada) for $1,200.
The New York Giants traded Butch Henline, Curt Walker and $30,000 to the Philadelphia Phillies for Irish Meusel.
The Detroit Tigers released Eddie Ainsmith.
The Detroit Tigers purchased Allen Conkwright from Bloomington (Three-I).
The Washington Senators purchased George Foss from Tampa (Florida State).
The Cincinnati Reds purchased Duke Gillespie from Calgary (Western Canada).
The Washington Senators purchased Bobby LaMotte from Tampa (Florida State).
The Cincinnati Reds purchased Karl Schnell from Calgary (Western Canada).
The St. Louis Cardinals signed Eddie Ainsmith as a free agent.
The Washington Senators selected Donie Bush off waivers from the Detroit Tigers.
The Boston Red Sox purchased Sam Dodge from Flint (Michigan-Ontario).
The Brooklyn Robins purchased Eddie Eayrs from the Boston Braves.
The Pittsburgh Pirates purchased Kiki Cuyler from Bay City (Michigan-Ontario).
The Washington Senators purchased Goose Goslin from Columbia (South Atlantic) for $7,000.
The Boston Braves purchased Jimmie Wilson from New Haven (Eastern).
The Cincinnati Reds drafted Ed Hock from Richmond (Virginia) in the 1921 rule 5 draft.
The Detroit Tigers traded Roy Crumpler, Sammy Hale, Jim Middleton, Joe Sargent, Suds Sutherland and $30,000 to Portland (PCL) for Syl Johnson and Herman Pillette.
The Chicago White Sox purchased Ferdie Schupp from the Brooklyn Robins.
The New York Giants traded George Burns, Mike Gonzalez and $150,000 to the Cincinnati Reds for Heinie Groh.
The New York Giants purchased Jimmy O'Connell from San Francisco (PCL) for $75,000.
The St. Louis Browns selected Chick Shorten off waivers from the Detroit Tigers.
Los Angeles (PCL) traded a player to be named later and Jigger Statz to the Chicago Cubs for a player to be named later. Los Angeles (PCL) sent Vic Aldridge (January, 1922) to the Chicago Cubs to complete the trade. The Chicago Cubs sent Elmer Ponder (January, 1922), John Sullivan (January, 1922), Babe Twombly (January, 1922), Tom Daly (February, 1922) and Charlie Deal (April, 1922) to Los Angeles (PCL) to complete the trade.
The New York Yankees traded Rip Collins, Roger Peckinpaugh, Bill Piercy and Jack Quinn to the Boston Red Sox for Joe Bush, Sam Jones and Everett Scott.
The Cleveland Indians traded George Burns, Joe Harris and Elmer Smith to the Boston Red Sox for Stuffy McInnis.
The Detroit Tigers selected George Cutshaw off waivers from the Pittsburgh Pirates.
Little Rock (Southern Association) traded an option on any player on team to the New York Giants for Joe Connolly.
Gabby Hartnett sent from Worcester (Eastern) to the Chicago Cubs in an unknown transaction.
The Philadelphia Phillies traded Snake Henry to New Orleans (Southern Association) for Roy Leslie.
Dave Keefe sent from the Philadelphia Athletics to the Cleveland Indians in an unknown transaction.
The Pittsburgh Pirates released Dave Robertson.
The Brooklyn Robins purchased Dazzy Vance from New Orleans (Southern Association).
Portland (PCL) purchased Frank Bruggy from the Philadelphia Phillies for $6,500.
The Washington Senators traded Jose Acosta and Bing Miller to the Philadelphia Athletics for Joe Dugan.
The Washington Senators traded Joe Dugan and Frank O'Rourke to the Boston Red Sox for Roger Peckinpaugh.
Louisville (American Association) purchased Lyman Lamb from the St. Louis Browns.
The Brooklyn Robins purchased Sam Crane from the Cincinnati Reds.
The Chicago White Sox purchased Jose Acosta from the Philadelphia Athletics.
The Philadelphia Athletics purchased Doc Johnston from the Cleveland Indians.
The Cincinnati Reds traded Larry Kopf and Rube Marquard to the Boston Braves for Jack Scott.
The Boston Red Sox selected Alex Ferguson off waivers from the New York Yankees.
The Brooklyn Robins purchased Possum Whitted from the Pittsburgh Pirates.