| 2012-01-01 | Jason Frasor | Toronto Blue Jays | Traded from White Sox to Blue Jays for Myles Jaye and Daniel Webb | MLB |
| 2012-01-01 | Myles Jaye | Chicago White Sox | Traded from Toronto Blue Jays with Daniel Webb to Chi White Sox for Jason Frasor | MLB |
| 2012-01-01 | Daniel Webb | Chicago White Sox | Traded from Toronto Blue Jays with Myles Jaye to Chi White Sox for Jason Frasor | MLB |
| 2012-01-05 | Carlos Zambrano | Miami Marlins | Traded from Chicago Cubs to Miami for Chris Volstad | MLB |
| 2012-01-05 | Chris Volstad | Chicago Cubs | Traded from Miami Marlins to Chi Cubs for Carlos Zambrano | MLB |
| 2012-01-05 | Greg Reynolds | Texas Rangers | Traded from Colorado Rockies to Texas for Chad Tracy | MLB |
| 2012-01-06 | Andrew Cashner | San Diego Padres | Traded from Chicago Cubs with Kyung-Min Na to San Diego for Anthony Rizzo and Zach Cates | MLB |
| 2012-01-06 | Anthony Rizzo | Chicago Cubs | Traded from San Diego Padres with Zach Cates to Chi Cubs for Andrew Cashner and Kyung-Min Na | MLB |
| 2012-01-06 | Kyung-Min Na | San Diego Padres | Traded from Cubs with Andrew Cashner to Padres for Anthony Rizzo and Zach Cates | AAA |
| 2012-01-16 | Seth Smith | Oakland Athletics | Traded from Colorado Rockies to Oakland for Guillermo Moscoso and Josh Outman | MLB |
| 2012-01-16 | Guillermo Moscoso | Colorado Rockies | Traded from Oakland Athletics with Josh Outman to Colorado for Seth Smith | MLB |
| 2012-01-16 | Josh Outman | Colorado Rockies | Traded from Oakland Athletics with Guillermo Moscoso to Colorado for Seth Smith | MLB |
| 2012-01-20 | Zach Putnam | Colorado Rockies | Traded from Indians to Rockies for Kevin Slowey | MLB |
| 2012-01-20 | Kevin Slowey | Cleveland Indians | Traded from Colorado Rockies to Cleveland Indians for Zach Putnam | MLB |
| 2012-01-21 | Marco Scutaro | Colorado Rockies | Traded from Red Sox to Rockies for Clayton Mortensen | MLB |
| 2012-01-21 | Clayton Mortensen | Boston Red Sox | Traded from Colorado Rockies to Boston for Marco Scutaro | MLB |
| 2012-01-23 | Jesus Montero | Seattle Mariners | Traded from New York Yankees with Hector Noesi to Seattle for Michael Pineda and Vicente Campos | MLB |
| 2012-01-23 | Hector Noesi | Seattle Mariners | Traded from New York Yankees with Jesus Montero to Seattle for Michael Pineda and Vicente Campos | MLB |
| 2012-01-23 | Michael Pineda | New York Yankees | Traded from Seattle Mariners with Vicente Campos to NY Yankees for Jesus Montero and Hector Noesi | MLB |
| 2012-01-23 | Jose Campos | New York Yankees | Traded from Seattle Mariners with Michael Pineda to NY Yankees for Jesus Montero and Hector Noesi | MLB |
| 2012-01-25 | Jeremy Horst | Philadelphia Phillies | Traded from Cincinnati Reds to Philadelphia for Wilson Valdez | MLB |
| 2012-01-25 | Wilson Valdez | Cincinnati Reds | Traded from Philadelphia Phillies to Cincinnati for Jeremy Horst | MLB |
| 2012-02-06 | Jeremy Guthrie | Colorado Rockies | Traded from Baltimore Orioles to Colorado for Jason Hammel and Matt Lindstrom | MLB |
| 2012-02-06 | Jason Hammel | Baltimore Orioles | Traded from Colorado Rockies with Matt Lindstrom to Baltimore for Jeremy Guthrie | MLB |
| 2012-02-06 | Matt Lindstrom | Baltimore Orioles | Traded from Colorado Rockies with Jason Hammel to Baltimore for Jeremy Guthrie | MLB |
| 2012-02-19 | Exicardo Cayones | New York Yankees | Traded from Pirates with Diego Moreno to Yankees for AJ Burnett | A+ |
| 2012-02-19 | A.J. Burnett | Pittsburgh Pirates | Traded from New York Yankees to Pittsburgh for Diego Moreno and Exicardo Cayones | MLB |
| 2012-02-19 | Diego Moreno | New York Yankees | Traded from Pittsburgh Pirates with Exicardo Cayones to NY Yankees for AJ Burnett | MLB |
| 2012-02-21 | Chris Carpenter | Boston Red Sox | Traded from Chicago Cubs with Aaron Kurcz to Boston for Jair Bogaerts (3/29/2012) | MLB |
| 2012-02-21 | Kelvin De La Cruz | Texas Rangers | Traded from Indians to Rangers for player to be named later | AAA |
| 2012-03-15 | Aaron Kurcz | Boston Red Sox | Traded from Cubs to Red Sox | AAA |
| 2012-03-20 | Kevin Chapman | Kansas City Royals | Traded from Astros to Royals with Jason Bourgeois and Humberto Quintero | MLB |
| 2012-03-20 | Jason Bourgeois | Kansas City Royals | Traded from Houston Astros with Humberto Quintero to KC Royals for Kevin Chapman and D`Andre Toney (6/10/2012) | MLB |
| 2012-03-20 | Humberto Quintero | Kansas City Royals | Traded from Houston Astros with Jason Bourgeois to KC Royals for Kevin Chapman and D`Andre Toney (6/10/2012) | MLB |
| 2012-03-28 | Christian Marrero | Atlanta Braves | Traded from White Sox to Braves | AAA |
| 2012-03-29 | Jairo Asencio | Cleveland Indians | Traded from Braves to Indians for cash considerations | MLB |
| 2012-03-30 | Matt Rizzotti | Minnesota Twins | Traded from Phillies to Twins for cash considerations | AAA |
| 2012-03-30 | Ryota Igarashi | Toronto Blue Jays | Traded from Pirates to Blue Jays for cash considerations | MLB |
| 2012-03-31 | Robby Rowland | Pittsburgh Pirates | Traded from Diamondbacks to Pirates for future considerations | AA |
| 2012-03-31 | Kyle Hudson | Tampa Bay Rays | Traded by Texas Rangers to Tampa Bay Rays for future considerations | MLB |
| 2012-04-01 | Juan Francisco | Atlanta Braves | Traded from Reds to Braves for J.J. Hoover | MLB |
| 2012-04-01 | J.J. Hoover | Cincinnati Reds | Traded from Braves to Reds for Juan Francisco | MLB |
| 2012-04-04 | Chris Stewart | New York Yankees | Traded from Giants to Yankees for George Kontos | MLB |
| 2012-04-04 | George Kontos | San Francisco Giants | Traded from Yankees to Giants for Chris Stewart | MLB |
| 2012-04-04 | Cedric Hunter | St. Louis Cardinals | Traded by Oakland Athletics to St. Louis Cardinals for future considerations | MLB |
| 2012-04-06 | Brian Tallet | San Diego Padres | Traded from Pirates to Padres | MLB |
| 2012-04-10 | Jose Castro | Chicago White Sox | Traded from Reds to White Sox for cash | AAA |
| 2012-04-19 | Zach Miner | Detroit Tigers | Traded from Royals to Tigers for cash considerations | MLB |
| 2012-04-21 | Michael Bowden | Chicago Cubs | Traded from Red Sox to Cubs for Marlon Byrd | MLB |
| 2012-04-21 | Josh Bell | Arizona Diamondbacks | Traded from Pirates to Diamondbacks for PTBNL | MLB |
| 2012-04-21 | Marlon Byrd | Boston Red Sox | Traded from Chicago Cubs to Boston for Mike Bowden and Hunter Cervenka (5/15/2012) | MLB |
| 2012-05-03 | Ernesto Frieri | Los Angeles Angels | Traded from Padres to Angels for Donn Roach and Alexi Amarista | MLB |
| 2012-05-03 | Alexi Amarista | San Diego Padres | Traded from Angels with Donn Roach to Padres for Ernesto Frieri | MLB |
| 2012-05-03 | Donn Roach | San Diego Padres | Traded from Angels with Alexi Amarista to Padres for Ernesto Frieri | MLB |
| 2012-05-04 | Ryan Spilborghs | Texas Rangers | Traded from Indians to Rangers for cash | MLB |
| 2012-05-07 | Loek Van Mil | Cleveland Indians | Traded from Angels to Indians | AAA |
| 2012-05-12 | Scott Podsednik | Boston Red Sox | Traded from Phillies to Red Sox | MLB |
| 2012-05-12 | Mike Belfiore | Baltimore Orioles | Traded from Arizona Diamondbacks to Baltimore for Josh Bell (4/21/2012) | MLB |
| 2012-05-15 | Hunter Cervenka | Chicago Cubs | Traded from Boston Red Sox with Mike Bowden to Chi Cubs for Marlon Byrd (4/21/2012) | MLB |
| 2012-05-16 | Kyle Hudson | Philadelphia Phillies | Traded from Tampa Bay Rays to Philadelphia for Rich Thompson | MLB |
| 2012-05-16 | Rich Thompson | Tampa Bay Rays | Traded from Philadelphia Phillies to Tampa Bay for Kyle Hudson | MLB |
| 2012-05-17 | Jamie Romak | St. Louis Cardinals | Traded from Royals for cash | MLB |
| 2012-05-19 | Koyie Hill | Chicago Cubs | Traded from Reds to Cubs + Contract purchased from minors | MLB |
| 2012-05-20 | Drew Sutton | Pittsburgh Pirates | Traded from Braves to Pirates | MLB |
| 2012-05-21 | Drew Sutton | Tampa Bay Rays | Traded from Pirates to Rays | MLB |
| 2012-05-24 | Paul Phillips | Toronto Blue Jays | Traded from Brewers for cash | MLB |
| 2012-05-26 | Justin Ruggiano | Miami Marlins | Traded from Houston Astros to Miami for Jobduan Morales | MLB |
| 2012-05-26 | Jobduan Morales | Houston Astros | Traded from Marlins with Jobduan Morales to Astros for Justin Ruggiano | A+ |
| 2012-06-02 | Steve Pearce | Baltimore Orioles | Traded from Yankees for cash | MLB |
| 2012-06-05 | Ruben Gotay | Atlanta Braves | Traded from Blue Jays to Braves | MLB |
| 2012-06-09 | Kris Watts | Washington Nationals | Traded from Pirates to Nationals for cash | AAA |
| 2012-06-12 | Esmil Rogers | Cleveland Indians | Traded from Rockies for cash | MLB |
| 2012-06-16 | Cole McCurry | Atlanta Braves | Traded from Orioles for cash | AAA |
| 2012-06-17 | Jason Christian | Atlanta Braves | Traded from Reds to Braves | AA |
| 2012-06-21 | Sean O'Sullivan | Toronto Blue Jays | Traded from Royals for cash considerations | MLB |
| 2012-06-22 | Beau Mills | Cincinnati Reds | Traded from Indians to Reds | AAA |
| 2012-06-24 | Brent Lillibridge | Boston Red Sox | Traded from White Sox with Zach Stewart for Kevin Youkilis | MLB |
| 2012-06-24 | Zach Stewart | Boston Red Sox | Traded from White Sox with Brent Lillibridge for Kevin Youkilis | MLB |
| 2012-06-24 | Kevin Youkilis | Chicago White Sox | Traded from Red Sox for Zach Stewart and Brent Lillibridge | MLB |
| 2012-06-27 | Shairon Martis | Minnesota Twins | Traded from Pirates to Twins | MLB |
| 2012-06-30 | Kyle Simon | Philadelphia Phillies | Traded from Orioles with Gabriel Lino for Jim Thome | AAA |
| 2012-07-01 | Jim Thome | Baltimore Orioles | Traded from Phillies to Orioles for Gabriel Lino and Kyle Simon | MLB |
| 2012-07-01 | Chad Qualls | New York Yankees | Traded from Phillies for PTNBL or Cash | MLB |
| 2012-07-01 | Gabriel Lino | Philadelphia Phillies | Traded from Orioles with Kyle Simon for Jim Thome | AAA |
| 2012-07-04 | Carlos Lee | Miami Marlins | Traded from Astros for Matt Dominguez and Rob Rasmussen | MLB |
| 2012-07-04 | Rob Rasmussen | Houston Astros | Traded from Marlins with Matt Dominguez for Carlos Lee | MLB |
| 2012-07-04 | Matt Dominguez | Houston Astros | Traded from Marlins with Rob Rasmussen for Carlos Lee | MLB |
| 2012-07-10 | Ozzie Martinez | Los Angeles Dodgers | Traded from White Sox for cash considerations | MLB |
| 2012-07-14 | Todd Redmond | Cincinnati Reds | Traded from Braves to Reds for Paul Janish | MLB |
| 2012-07-14 | Paul Janish | Atlanta Braves | Traded from Reds to Braves for Todd Redmond | MLB |
| 2012-07-19 | Justin Germano | Chicago Cubs | Traded from Red Sox to Cubs | MLB |
| 2012-07-19 | Dan Brewer | Atlanta Braves | Traded from Yankees to Braves | AAA |
| 2012-07-20 | Jonathan Sanchez | Colorado Rockies | Traded from Royals to Rockies for Jeremy Guthrie | MLB |
| 2012-07-20 | Jeremy Guthrie | Kansas City Royals | Traded from Rockies to Royals for Jonathan Sanchez | MLB |
| 2012-07-20 | Francisco Cordero | Houston Astros | Traded from Blue Jays to Astros in 10-player deal | MLB |
| 2012-07-20 | Joe Musgrove | Houston Astros | Traded from Blue Jays to Astros in 10-player deal | MLB |
| 2012-07-20 | David Rollins | Houston Astros | Traded from Blue Jays to Astros in 10-player deal | MLB |
| 2012-07-20 | Brandon Lyon | Toronto Blue Jays | Traded from Astros to Blue Jays in 10-player deal | MLB |
| 2012-07-20 | J.A. Happ | Toronto Blue Jays | Traded from Astros to Blue Jays in 10-player deal | MLB |
| 2012-07-20 | Omar Quintanilla | Baltimore Orioles | Traded from Mets to Orioles | MLB |
| 2012-07-20 | David Carpenter | Toronto Blue Jays | Traded from Astros to Blue Jays in 10-player deal | MLB |
| 2012-07-20 | Carlos Perez | Houston Astros | Traded from Blue Jays to Astros in 10-player deal | MLB |
| 2012-07-20 | Asher Wojciechowski | Houston Astros | Traded from Blue Jays to Astros in 10-player deal | MLB |
| 2012-07-20 | Ben Francisco | Houston Astros | Traded from Toronto Blue Jays with Francisco Cordero, Asher Wojciechowski, Carlos Perez, David Rollins, Joe Musgrove and Kevin Comer to Houston for J.A. Happ, David Carpenter and Brandon Lyon | MLB |
| 2012-07-22 | Brett Myers | Chicago White Sox | Traded from Astros to White Sox for Matt Heidenreich, Blair Walters and a PTNBL (Chris Devenski) | MLB |
| 2012-07-22 | Matt Heidenreich | Houston Astros | Traded from White Sox to Astros with Blair Walters and PTNBL for Brett Myers | AA |
| 2012-07-22 | Blair Walters | Houston Astros | Traded from White Sox to Astros with Matt Heidenreich and PTNBL for Brett Myers | AAA |
| 2012-07-23 | Omar Infante | Detroit Tigers | Traded from Marlins with Anibal Sanchez to Tigers for Jacob Turner, Rob Brantly and Brian Flynn | MLB |
| 2012-07-23 | Anibal Sanchez | Detroit Tigers | Traded from Marlins with Omar Infante to Tigers for Jacob Turner, Rob Brantly and Brian Flynn | MLB |
| 2012-07-23 | Jacob Turner | Miami Marlins | Traded from Tigers with Rob Brantly and Brian Flynn to Marlins for Anibal Sanchez and Omar Infante | MLB |
| 2012-07-23 | D.J. Mitchell | Seattle Mariners | Traded from Yankees with Danny Farquhar to Mariners for Ichiro Suzuki | MLB |
| 2012-07-23 | Ichiro Suzuki | New York Yankees | Traded from Mariners to Yankees for D.J. Mitchell and Danny Farquhar | MLB |
| 2012-07-23 | Rob Brantly | Miami Marlins | Traded from Tigers with Jacob Turner and Brian Flynn to Marlins for Anibal Sanchez and Omar Infante | MLB |
| 2012-07-23 | Brian Flynn | Miami Marlins | Traded from Tigers with Jacob Turner and Rob Brantly to Marlins for Anibal Sanchez and Omar Infante | MLB |
| 2012-07-23 | Danny Farquhar | Seattle Mariners | Traded from Yankees with D.J. Mitchell to Mariners for Ichiro Suzuki | MLB |
| 2012-07-23 | Barry Enright | Los Angeles Angels | Traded from Arizona Diamondbacks to LA Angels for Frazier Hall (8/31/2012) | MLB |
| 2012-07-24 | Barry Enright | Los Angeles Angels | Traded from Diamondbacks to Angels for future considerations | MLB |
| 2012-07-24 | Brent Lillibridge | Cleveland Indians | Traded from Red Sox to Indians for Jose de la Torre | MLB |
| 2012-07-24 | Jose De La Torre | Boston Red Sox | Traded from Indians to Red Sox for Brent Lillibridge | MLB |
| 2012-07-24 | Wandy Rodriguez | Pittsburgh Pirates | Traded from Astros to Pirates for Rudy Owens, Robbie Grossman and Colton Cain | MLB |
| 2012-07-24 | Colton Cain | Houston Astros | Traded from Pirates with Robbie Grossman and Rudy Owens to Astros for Wandy Rodriguez | AA |
| 2012-07-24 | Rudy Owens | Houston Astros | Traded from Pirates with Robbie Grossman and Colton Cain to Astros for Wandy Rodriguez | MLB |
| 2012-07-24 | Robbie Grossman | Houston Astros | Traded from Pirates with Colton Cain and Rudy Owens to Astros for Wandy Rodriguez | MLB |
| 2012-07-25 | Randy Choate | Los Angeles Dodgers | Traded from Marlins with Hanley Ramirez to Dodgers for Nathan Eovaldi and Scott McGough | MLB |
| 2012-07-25 | Hanley Ramirez | Los Angeles Dodgers | Traded from Marlins with Randy Choate to Dodgers for Nathan Eovaldi and Scott Mcgough | MLB |
| 2012-07-25 | Nathan Eovaldi | Miami Marlins | Traded from Dodgers with Scott McGough to Marlins for Randy Choate and Hanley Ramirez | MLB |
| 2012-07-25 | Ryan Roberts | Tampa Bay Rays | Traded from Diamondbacks to Rays for Tyler Bortnick | MLB |
| 2012-07-25 | Tyler Bortnick | Arizona Diamondbacks | Traded from Rays to Diamondbacks for Ryan Roberts | AAA |
| 2012-07-25 | Scott McGough | Miami Marlins | Traded from Dodgers with Nathan Eovaldi to Marlins for Randy Choate and Hanley Ramirez | MLB |
| 2012-07-26 | Brad Davis | Detroit Tigers | Traded from Marlins to Tigers for future considerations | MLB |
| 2012-07-27 | Jean Segura | Milwaukee Brewers | Traded from Angels with Johnny Hellweg and Ariel Pena to Brewers for Zack Greinke | MLB |
| 2012-07-27 | Ariel Pena | Milwaukee Brewers | Traded from Angels with Johnny Hellweg and Jean Segura to Brewers for Zack Greinke | MLB |
| 2012-07-27 | Zack Greinke | Los Angeles Angels | Traded from Brewers to Angels for Jean Segura, Johnny Hellweg and Arial Pena | MLB |
| 2012-07-27 | Johnny Hellweg | Milwaukee Brewers | Traded from Angels with Jean Segura and Ariel Pena to Brewers for Zack Greinke | MLB |
| 2012-07-28 | Marco Scutaro | San Francisco Giants | Traded from Rockies to Giants for Charlie Culberson | MLB |
| 2012-07-28 | Charlie Culberson | Colorado Rockies | Traded from Giants to Rockies for Marco Scutaro | MLB |
| 2012-07-28 | George Kottaras | Oakland Athletics | Traded from Milwaukee Brewers to Oakland for Fautino De Los Santos | MLB |
| 2012-07-28 | Eduardo Escobar | Minnesota Twins | Traded from Chicago White Sox with Pedro Hernandez to Minnesota for Francisco Liriano | MLB |
| 2012-07-28 | Pedro Hernandez | Minnesota Twins | Traded from Chicago White Sox with Eduardo Escobar to Minnesota for Francisco Liriano | MLB |
| 2012-07-29 | Francisco Liriano | Chicago White Sox | Traded from Twins to White Sox for Eduardo Escobar and Pedro Hernandez | MLB |
| 2012-07-29 | Eduardo Escobar | Minnesota Twins | Traded from White Sox with Pedro Hernandez to Twins for Francisco Liriano | MLB |
| 2012-07-29 | Pedro Hernandez | Minnesota Twins | Traded from White Sox with Eduardo Escobar to Twins for Francisco Liriano | MLB |
| 2012-07-29 | George Kottaras | Oakland Athletics | Traded from Brewers to Athletics for Fautino de los Santos | MLB |
| 2012-07-29 | Chris Johnson | Arizona Diamondbacks | Traded from Astros to Diamondbacks for Bobby Borchering and Marc Krauss | MLB |
| 2012-07-29 | Christian Marrero | Pittsburgh Pirates | Traded from Braves to Pirates for Brian Friday | AAA |
| 2012-07-29 | Brian Friday | Atlanta Braves | Traded from Pirates to Braves for Christian Marrero | AAA |
| 2012-07-29 | Bobby Borchering | Houston Astros | Traded from Diamondbacks with Marc Krauss to Astros for Chris Johnson | AA |
| 2012-07-29 | Marc Krauss | Houston Astros | Traded from Diamondbacks with Bobby Borchering to Astros for Chris Johnson | MLB |
| 2012-07-29 | Fautino De Los Santos | Milwaukee Brewers | Traded from Athletics to Brewers for George Kottaras | MLB |
| 2012-07-30 | Travis Snider | Pittsburgh Pirates | Traded from Toronto Blue Jays to Pittsburgh for Brad Lincoln | MLB |
| 2012-07-30 | Brad Lincoln | Toronto Blue Jays | Traded from Pittsburgh Pirates to Toronto for Travis Snider | MLB |
| 2012-07-30 | Brandon League | Los Angeles Dodgers | Traded from Seattle Mariners to LA Dodgers for Leon Landry and Logan Bawcom | MLB |
| 2012-07-31 | Eric Thames | Seattle Mariners | Traded from Blue Jays to Mariners for Steve Delabar | MLB |
| 2012-07-31 | Steve Delabar | Toronto Blue Jays | Traded from Mariners to Blue Jays for Eric Thames | MLB |
| 2012-07-31 | Brad Lincoln | Toronto Blue Jays | Traded from Pirates to Blue Jays for Travis Snider | MLB |
| 2012-07-31 | Travis Snider | Pittsburgh Pirates | Traded from Blue Jays to Pirates for Brad Lincoln | MLB |
| 2012-07-31 | Reed Johnson | Atlanta Braves | Traded from Cubs with Paul Maholm to Braves for Arodys Vizcaino and Jaye Chapman | MLB |
| 2012-07-31 | Paul Maholm | Atlanta Braves | Traded from Cubs with Reed Johnson to Braves for Arodys Vizcaino and Jaye Chapman | MLB |
| 2012-07-31 | Arodys Vizcaino | Chicago Cubs | Traded from Braves with Jaye Chapman to Cubs for Paul Maholm and Reed Johnson | MLB |
| 2012-07-31 | Jaye Chapman | Chicago Cubs | Traded from Braves with Arodys Vizcaino to Cubs for Paul Maholm and Reed Johnson | MLB |
| 2012-07-31 | Brandon League | Los Angeles Dodgers | Traded from Mariners to Dodgers for Logan Bawcom and Leon Landry | MLB |
| 2012-07-31 | Logan Bawcom | Seattle Mariners | Traded from Dodgers with Leon Landry to Mariners for Brandon League | AAA |
| 2012-07-31 | Leon Landry | Seattle Mariners | Traded from Dodgers with Logan Bawcom to Mariners for Brandon League | AAA |
| 2012-07-31 | Geovany Soto | Texas Rangers | Traded from Cubs to Rangers for Jacob Brigham | MLB |
| 2012-07-31 | Jake Brigham | Chicago Cubs | Traded from Rangers to Cubs for Geovany Soto | MLB |
| 2012-07-31 | Shane Victorino | Los Angeles Dodgers | Traded from Phillies with PTNBL to Dodgers for Josh Lindblom and Ethan Martin | MLB |
| 2012-07-31 | Josh Lindblom | Philadelphia Phillies | Traded from Dodgers with Ethan Martin to Phillies for Shane Victorino | MLB |
| 2012-07-31 | Hunter Pence | San Francisco Giants | Traded from Phillies to Giants for Nate Schierholtz, Seth Rosin and Tommy Joseph | MLB |
| 2012-07-31 | Nate Schierholtz | Philadelphia Phillies | Traded from Giants with Tommy Joseph and Seth Rosin to Phillies for Hunter Pence | MLB |
| 2012-07-31 | Seth Rosin | Philadelphia Phillies | Traded from Giants with Tommy Joseph and Nate Schierholtz to Phillies for Hunter Pence | MLB |
| 2012-07-31 | Craig Breslow | Boston Red Sox | Traded from Diamondbacks to Red Sox for Scott Podsednik and Matt Albers | MLB |
| 2012-07-31 | Matt Albers | Arizona Diamondbacks | Traded from Red Sox with Scott Podsednik to Diamondbacks for Craig Breslow | MLB |
| 2012-07-31 | Scott Podsednik | Arizona Diamondbacks | Traded from Red Sox with Matt Albers to Diamondbacks for Craig Breslow | MLB |
| 2012-07-31 | Gaby Sanchez | Pittsburgh Pirates | Traded from Marlins with Kyle Kaminska to Pirates for Gorkys Hernandez | MLB |
| 2012-07-31 | Gorkys Hernandez | Miami Marlins | Traded from Pirates to Marlins for Gaby Sanchez and Kyle Kaminska | MLB |
| 2012-07-31 | Edward Mujica | St. Louis Cardinals | Traded from Marlins to Cardinals for Zach Cox | MLB |
| 2012-07-31 | Zack Cox | Miami Marlins | Traded from Cardinals to Pirates for Edward Mujica | AAA |
| 2012-07-31 | Lars Anderson | Cleveland Indians | Traded from Red Sox to Indians for Steven Wright | MLB |
| 2012-07-31 | Jonathan Broxton | Cincinnati Reds | Traded from Royals to Reds for Donnie Joseph and J.C. Sulbaran | MLB |
| 2012-07-31 | Donnie Joseph | Kansas City Royals | Traded from Reds with J.C. Sulbaran to Royals for Jonathan Broxton | MLB |
| 2012-07-31 | Chad Qualls | Pittsburgh Pirates | Traded from Yankees to Pirates for Casey McGehee | MLB |
| 2012-07-31 | Casey McGehee | New York Yankees | Traded from Pirates to Yankees for Chad Qualls | MLB |
| 2012-07-31 | Ryan Dempster | Texas Rangers | Traded from Cubs to Rangers for Kyle Hendricks and Christian Villaneuva | MLB |
| 2012-07-31 | Christian Villanueva | Chicago Cubs | Traded from Rangers with Kyle Hendricks to Cubs for Ryan Dempster | MLB |
| 2012-07-31 | Kyle Hendricks | Chicago Cubs | Traded from Rangers with Christian Villaneuva to Cubs for Ryan Dempster | MLB |
| 2012-07-31 | Ethan Martin | Philadelphia Phillies | Traded from Dodgers with Josh Lindblom to Phillies for Shane Victorino | MLB |
| 2012-07-31 | Tommy Joseph | Philadelphia Phillies | Traded from Giants with Nate Schierholtz and Seth Rosin to Phillies for Hunter Pence | MLB |
| 2012-07-31 | Steven Wright | Boston Red Sox | Traded from Indians to Red Sox for Lars Anderson | MLB |
| 2012-07-31 | Kyle Kaminska | Pittsburgh Pirates | Traded from Marlins with Gaby Sanchez to Pirates for Gorkys Hernandez | AAA |
| 2012-07-31 | Juan Carlos Sulbaran | Kansas City Royals | Traded from Reds with Donnie Joseph to Royals for Jonathan Broxton | AAA |
| 2012-08-03 | Kurt Suzuki | Washington Nationals | Traded from Athletics to Nationals for David Freitas | MLB |
| 2012-08-03 | David Freitas | Oakland Athletics | Traded from Nationals to Athletics for Kurt Suzuki | MLB |
| 2012-08-03 | Garrett Mock | Houston Astros | Traded by Boston Red Sox to Houston Astros for future considerations | MLB |
| 2012-08-03 | Chris Devenski | Houston Astros | Traded from Chicago White Sox with Blair Walters and Matt Heidenreich to Houston for Brett Myers (7/21/2012) | MLB |
| 2012-08-03 | Joe Blanton | Los Angeles Dodgers | Traded from Philadelphia Phillies to LA Dodgers for Ryan O`Sullivan (8/16/2012) | MLB |
| 2012-08-04 | Pat Neshek | Oakland Athletics | Traded from Orioles to Athletics for future considerations + Contract purchased | MLB |
| 2012-08-04 | Tuffy Gosewisch | Toronto Blue Jays | Traded from Phillies to Blue Jays | MLB |
| 2012-08-05 | Danny Valencia | Boston Red Sox | Traded from Twins to Red Sox for Jeremias Pineda | MLB |
| 2012-08-05 | Jeremias Pineda | Minnesota Twins | Traded from Red Sox to Twins for Danny Valencia | AAA |
| 2012-08-05 | Jeff Baker | Detroit Tigers | Traded from Chicago Cubs to Detroit for Marcelo Carreno (10/16/2012) | MLB |
| 2012-08-09 | Tyler Greene | Houston Astros | Traded from Cardinals to Astros for future considerations | MLB |
| 2012-08-10 | Tyler Kuhn | Arizona Diamondbacks | Traded from White Sox to Diamondbacks for cash | AAA |
| 2012-08-13 | Carlos Rojas | Cleveland Indians | Traded from Orioles to Indians for J.C. Romero | AAA |
| 2012-08-13 | J.C. Romero | Baltimore Orioles | Traded from Cleveland Indians to Baltimore for Carlos Rojas | MLB |
| 2012-08-14 | Kelly Shoppach | New York Mets | Traded from Red Sox to Mets for future considerations (Pedro Beato) | MLB |
| 2012-08-16 | Daniel Cabrera | Arizona Diamondbacks | Traded from Pirates to Diamondbacks for future considerations | MLB |
| 2012-08-16 | Pedro Beato | Boston Red Sox | Traded from Mets to Red Sox to complete Kelly Shoppach trade on Aug 14 | MLB |
| 2012-08-16 | Ryan O'Sullivan | Philadelphia Phillies | Traded from Dodgers to Phillies | AA |
| 2012-08-16 | Kevin Comer | Houston Astros | Traded from Blue Jays to Astros to complete trade from July 20 | AAA |
| 2012-08-22 | Stephen Drew | Oakland Athletics | Traded from Diamondbacks to Athletics for Sean Jamieson | MLB |
| 2012-08-22 | Sean Jamieson | Arizona Diamondbacks | Traded from Athletics to Diamondbacks for Stephen Drew | AAA |
| 2012-08-24 | Jesse Chavez | Oakland Athletics | Traded from Blue Jays to Athletics for cash | MLB |
| 2012-08-25 | Ivan De Jesus | Boston Red Sox | Traded from Dodgers with James Loney, Jerry Sands, Rubby de la Rosa and Allen Webster to Red Sox for Josh Beckett, Adrian Gonzalez, Carl Crawford and Nick Punto | MLB |
| 2012-08-25 | James Loney | Boston Red Sox | Traded from Dodgers with Ivan DeJesus, Jerry Sands, Rubby de la Rosa and Allen Webster to Red Sox for Josh Beckett, Adrian Gonzalez, Carl Crawford and Nick Punto | MLB |
| 2012-08-25 | Jerry Sands | Boston Red Sox | Traded from Dodgers with James Loney, Ivan DeJesus, Rubby de la Rosa and Allen Webster to Red Sox for Josh Beckett, Adrian Gonzalez, Carl Crawford and Nick Punto | MLB |
| 2012-08-25 | Allen Webster | Boston Red Sox | Traded from Dodgers with James Loney, Jerry Sands, Rubby de la Rosa and Ivan DeJesus to Red Sox for Josh Beckett, Adrian Gonzalez, Carl Crawford and Nick Punto | MLB |
| 2012-08-25 | Josh Beckett | Los Angeles Dodgers | Traded from Red Sox with Adrian Gonzalez, Carl Crawford and Nick Punto to Dodgers for Jerry Sands, James Loney, Ivan DeJesus, Rubby de la Rosa and Allen Webster | MLB |
| 2012-08-25 | Adrian Gonzalez | Los Angeles Dodgers | Traded from Red Sox with Josh Beckett, Carl Crawford and Nick Punto to Dodgers for Jerry Sands, James Loney, Ivan DeJesus, Rubby de la Rosa and Allen Webster | MLB |
| 2012-08-25 | Nick Punto | Los Angeles Dodgers | Traded from Red Sox with Adrian Gonzalez, Carl Crawford and Josh Beckett to Dodgers for Jerry Sands, James Loney, Ivan DeJesus, Rubby de la Rosa and Allen Webster | MLB |
| 2012-08-25 | Carl Crawford | Los Angeles Dodgers | Traded from Red Sox with Adrian Gonzalez, Josh Beckett and Nick Punto to Dodgers for Jerry Sands, James Loney, Ivan DeJesus, Rubby de la Rosa and Allen Webster | MLB |
| 2012-08-26 | Matt Lindstrom | Arizona Diamondbacks | Traded from Orioles to Diamondbacks for Joe Saunders | MLB |
| 2012-08-26 | Joe Saunders | Baltimore Orioles | Traded from Diamondbacks to Orioles for Matt Lindstrom | MLB |
| 2012-08-27 | Steve Pearce | New York Yankees | Traded from Astros to Yankees for cash considerations | MLB |
| 2012-08-27 | Anthony Recker | Chicago Cubs | Traded from Athletics to Cubs for Blake Lalli | MLB |
| 2012-08-27 | Blake Lalli | Oakland Athletics | Traded from Cubs to Athletics for Anthony Recker | MLB |
| 2012-08-31 | Ben Francisco | Tampa Bay Rays | Traded from Houston Astros to Tampa Bay for Theron Geith (9/21/2012) | MLB |
| 2012-09-01 | Jeff Baker | Atlanta Braves | Traded from Detroit Tigers to Atlanta for Greg Ross (9/25/2012) | MLB |
| 2012-09-02 | Frazier Hall | Arizona Diamondbacks | Traded from Angels to Diamondbacks | A |
| 2012-09-05 | Guillermo Quiroz | Boston Red Sox | Traded from Mariners to Red Sox for cash considerations | MLB |
| 2012-09-21 | Theron Geith | Houston Astros | Traded from Rays to Astros as PTBNL from August 31 trade | AA |
| 2012-09-22 | Yorvit Torrealba | Milwaukee Brewers | Traded from Blue Jays to Brewers | MLB |
| 2012-09-25 | Greg Ross | Detroit Tigers | Traded from Braves to Tigers to complete Aug 31 trade. | AAA |
| 2012-09-28 | Stefan Jarrin | Philadelphia Phillies | Traded from Dodgers to Phillies | Rk |
| 2012-10-04 | Rubby De La Rosa | Boston Red Sox | Traded from Los Angeles Dodgers with James Loney, Ivan De Jesus, Allen Webster and Jerry Sands to Boston for Josh Beckett (8/25/2012), Adrian Gonzalez (8/25/2012), Carl Crawford (8/25/2012) and Nick Punto (8/25/2012) | MLB |
| 2012-10-04 | Jerry Sands | Boston Red Sox | Traded from Los Angeles Dodgers with James Loney, Ivan De Jesus, Allen Webster and Rubby De La Rosa to Boston for Josh Beckett (8/25/2012), Adrian Gonzalez (8/25/2012), Carl Crawford (8/25/2012) and Nick Punto (8/25/2012) | MLB |
| 2012-10-16 | Marcelo Carreno | Chicago Cubs | Traded from Tigers to Cubs | A |
| 2012-10-20 | Chris Young | Oakland Athletics | Traded from Diamondbacks to Athletics for Cliff Pennington and Yordy Cabrera | MLB |
| 2012-10-20 | Heath Bell | Arizona Diamondbacks | Traded from Miami Marlins with Cliff Pennington to Arizona for Yordy Cabrera | MLB |
| 2012-10-21 | David Carpenter | Boston Red Sox | Traded from Blue Jays to Red Sox for Mike Aviles | MLB |
| 2012-10-21 | Mike Aviles | Toronto Blue Jays | Traded from Red Sox to Blue Jays for David Carpenter | MLB |
| 2012-10-21 | Cliff Pennington | Arizona Diamondbacks | Traded from Athletics with Yordy Cabrera to Diamondbacks for Chris Young | MLB |
| 2012-10-21 | Yordy Cabrera | Arizona Diamondbacks | Traded from Athletics with Cliff Pennington to Diamonbacks for Chris Young | AAA |
| 2012-10-21 | John Farrell | Boston Red Sox | Traded from Toronto Blue Jays with David Carpenter to Boston for Mike Aviles | MLB |
| 2012-10-22 | Yordy Cabrera | Miami Marlins | Traded from Diamondbacks to Marlins for Heath Bell | AAA |
| 2012-10-31 | Brandon Sisk | Los Angeles Angels | Traded from Royals to Angels for Ervin Santana | AAA |
| 2012-11-01 | Ervin Santana | Kansas City Royals | Traded from Angels to Royals for Brandon Sisk | MLB |
| 2012-11-03 | Mike Aviles | Cleveland Indians | Traded from Blue Jays with Yan Gomes to Indians for Esmil Rogers | MLB |
| 2012-11-03 | Yan Gomes | Cleveland Indians | Traded from Blue Jays with Mike Aviles to Indians for Esmil Rogers | MLB |
| 2012-11-03 | Esmil Rogers | Toronto Blue Jays | Traded from Indians to Blue Jays for Mike Aviles and Yan Gomes | MLB |
| 2012-11-07 | Blake Tekotte | Chicago White Sox | Traded from Padres to White Sox for Brandon Kloess | MLB |
| 2012-11-07 | Branch Kloess | San Diego Padres | Traded from White Sox to Padres for Blake Tekotte | AAA |
| 2012-11-08 | Jeremy Jeffress | Toronto Blue Jays | Traded from Royals to Blue Jays for cash considerations | MLB |
| 2012-11-08 | Kenneth Williams | Colorado Rockies | Traded from White Sox to Rockies for Mark Tracy | AA |
| 2012-11-08 | Mark Tracy | Chicago White Sox | Traded from Rockies to White Sox for Kenny Williams Jr. | A+ |
| 2012-11-08 | Tommy Hottovy | Texas Rangers | Traded from Kansas City Royals to Texas for Desmond Henry (3/27/2013) | MLB |
| 2012-11-16 | Tyson Ross | San Diego Padres | Traded from Athletics with A.J. Kirby-Jones to Padres for Andy Parrino and Andrew Werner | MLB |
| 2012-11-16 | A.J. Kirby-Jones | San Diego Padres | Traded from Athletics with Tyson Ross to Padres for Andy Parrino and Andrew Werner | AA |
| 2012-11-16 | Andy Parrino | Oakland Athletics | Traded from Padres with Andrew Werner to Athletics for Tyson Ross and A.J. Kirby-Jones | MLB |
| 2012-11-16 | Andrew Werner | Oakland Athletics | Traded from Padres with Andy Parrino to Athletics for Tyson Ross and A.J. Kirby-Jones | MLB |
| 2012-11-19 | Mark Buehrle | Toronto Blue Jays | Traded from Marlins with John Buck, Emilio Bonifacio, Josh Johnson and Jose Reyes to Blue Jays for Henderson Alvarez, Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick | MLB |
| 2012-11-19 | Josh Johnson | Toronto Blue Jays | Traded from Marlins with John Buck, Mark Buehrle, Emilio Bonifacio and Jose Reyes to Blue Jays for Henderson Alvarez, Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick | MLB |
| 2012-11-19 | John Buck | Toronto Blue Jays | Traded from Marlins with Emilio Bonifacio, Mark Buehrle, Josh Johnson and Jose Reyes to Blue Jays for Henderson Alvarez, Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick | MLB |
| 2012-11-19 | Emilio Bonifacio | Toronto Blue Jays | Traded from Marlins with John Buck, Mark Buehrle, Josh Johnson and Jose Reyes to Blue Jays for Henderson Alvarez, Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick | MLB |
| 2012-11-19 | Jose Reyes | Toronto Blue Jays | Traded from Marlins with John Buck, Mark Buehrle, Josh Johnson and Emilio Bonifacio to Blue Jays for Henderson Alvarez, Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick | MLB |
| 2012-11-19 | Henderson Alvarez | Miami Marlins | Traded from Blue Jays with Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick to Marlins for Emilio Bonifacio, John Buck, Mark Buehrle, Josh Johnson and Jose Reyes | MLB |
| 2012-11-19 | Yunel Escobar | Miami Marlins | Traded from Blue Jays with Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick to Marlins for Emilio Bonifacio, John Buck, Mark Buehrle, Josh Johnson and Jose Reyes | MLB |
| 2012-11-19 | Jeff Mathis | Miami Marlins | Traded from Blue Jays with Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick to Marlins for Emilio Bonifacio, John Buck, Mark Buehrle, Josh Johnson and Jose Reyes | MLB |
| 2012-11-19 | Adeiny Hechavarria | Miami Marlins | Traded from Blue Jays with Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick to Marlins for Emilio Bonifacio, John Buck, Mark Buehrle, Josh Johnson and Jose Reyes | MLB |
| 2012-11-19 | Anthony DeSclafani | Miami Marlins | Traded from Blue Jays with Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick to Marlins for Emilio Bonifacio, John Buck, Mark Buehrle, Josh Johnson and Jose Reyes | MLB |
| 2012-11-19 | Justin Nicolino | Miami Marlins | Traded from Blue Jays with Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick to Marlins for Emilio Bonifacio, John Buck, Mark Buehrle, Josh Johnson and Jose Reyes | MLB |
| 2012-11-19 | Jake Marisnick | Miami Marlins | Traded from Blue Jays with Yunel Escobar, Adeiny Hechavarria, Jeff Mathis, Anthony DeSclafani, Justin Nicolino and Jake Marisnick to Marlins for Emilio Bonifacio, John Buck, Mark Buehrle, Josh Johnson and Jose Reyes | MLB |
| 2012-11-20 | Robert Andino | Seattle Mariners | Traded from Orioles to Mariners for Trayvon Robinson | MLB |
| 2012-11-20 | Trayvon Robinson | Baltimore Orioles | Traded from Mariners to Orioles for Robert Andino | MLB |
| 2012-11-20 | Ryan Wheeler | Colorado Rockies | Traded from Diamondbacks to Rockies for Matt Reynolds | MLB |
| 2012-11-20 | Matt Reynolds | Arizona Diamondbacks | Traded from Rockies to Diamondbacks for Ryan Wheeler | MLB |
| 2012-11-21 | Jake Brigham | Texas Rangers | Traded from Cubs to Rangers for Barrett Loux and PTBNL | MLB |
| 2012-11-21 | Barret Loux | Chicago Cubs | Traded from Rangers with PTBNL to Cubs for Jacob Brigham | AAA |
| 2012-11-26 | Brandon Hicks | New York Mets | Traded from Mets to Athletics for cash considerations | MLB |
| 2012-11-28 | Vin Mazzaro | Pittsburgh Pirates | Traded from Royals with Clint Robinson to Pirates for Luis Rico and Luis Santos | MLB |
| 2012-11-28 | Clint Robinson | Pittsburgh Pirates | Traded from Royals with Vin Mazzaro to Pirates for Luis Rico and Luis Santos | MLB |
| 2012-11-28 | Zach Stewart | Pittsburgh Pirates | Traded from Red Sox to Pirates for PTBNL | MLB |
| 2012-11-28 | Danny Valencia | Baltimore Orioles | Traded from Red Sox to Orioles for cash considerations | MLB |
| 2012-11-28 | Sandy Rosario | Oakland Athletics | Traded from Red Sox to Athletics for future considerations | MLB |
| 2012-11-28 | Cory Burns | Texas Rangers | Traded from Padres to Rangersfor future considerations | MLB |
| 2012-11-28 | Luis Rico | Kansas City Royals | Traded from Pirates with Luis Santos to Royals for Vin Mazzaro and Clint Robinson | AA |
| 2012-11-28 | Luis Santos | Kansas City Royals | Traded from Pittsburgh Pirates with Luis Rico to KC Royals for Vincent Mazzaro and Clint Robinson | MLB |
| 2012-11-29 | Denard Span | Washington Nationals | Traded from Twins to Nationals for Alex Meyer | MLB |
| 2012-11-29 | Alex Meyer | Minnesota Twins | Traded from Nationals to Twins for Denard Span | MLB |
| 2012-11-30 | Yamaico Navarro | Baltimore Orioles | Traded from Pirates to Orioles for Jhondaniel Medina | MLB |
| 2012-11-30 | Jhondaniel Medina | Pittsburgh Pirates | Traded from Orioles to Pirates for Yamaico Navarro | AAA |
| 2012-11-30 | Tommy Hanson | Los Angeles Angels | Traded from Braves to Angels for Jordan Walden | MLB |
| 2012-11-30 | Jordan Walden | Atlanta Braves | Traded from Angels to Braves for Tommy Hanson | MLB |
| 2012-11-30 | Chris Resop | Oakland Athletics | Traded from Pirates to Athletics for Zach Thornton | MLB |
| 2012-11-30 | Zack Thornton | Pittsburgh Pirates | Traded from Athletics to Pirates for Chris Resop | AAA |
| 2012-12-01 | Burke Badenhop | Milwaukee Brewers | Traded from Rays to Brewers for Raul Mondesi Jr. | MLB |
| 2012-12-04 | Alex White | Houston Astros | Traded from Colorado Rockies with Alex Gillingham to Houston for Wilton Lopez and Jose Monzon (5/1/2013) | MLB |
| 2012-12-05 | Alex White | Houston Astros | Traded from Rockies with Alex Gillingham to Astros for Wilton Lopez and PTBNL or Cash | MLB |
| 2012-12-05 | Alex Gillingham | Houston Astros | Traded from Rockies with Alex White to Astros for Wilton Lopez and PTBNL or Cash | A+ |
| 2012-12-05 | Wilton Lopez | Colorado Rockies | Traded from Astros with PTBNL to Rockies for Alex White and Alex Gillingham | MLB |
| 2012-12-05 | Yunel Escobar | Tampa Bay Rays | Traded from Marlins to Rays for Derek Dietrich | MLB |
| 2012-12-05 | Derek Dietrich | Miami Marlins | Traded from Rays to Marlins for Yunel Escobar | MLB |
| 2012-12-05 | Andy Oliver | Pittsburgh Pirates | Traded from Tigers to Pirates for Ramon Cabrera | MLB |
| 2012-12-05 | Ramon Cabrera | Detroit Tigers | Traded from Pirates to Tigers for Andy Oliver | MLB |
| 2012-12-06 | Justin Henry | Boston Red Sox | Traded from Tigers to Red Sox for Jeff Kobernus | AAA |
| 2012-12-06 | Vance Worley | Minnesota Twins | Traded from Phillies with Trevor May to Twins for Ben Revere | MLB |
| 2012-12-06 | Trevor May | Minnesota Twins | Traded from Phillies with Vance Worley to Twins for Ben Revere | MLB |
| 2012-12-06 | Ben Revere | Philadelphia Phillies | Traded from Twins to Phillies for Vance Worley and Trevor May | MLB |
| 2012-12-06 | Wilfredo Boscan | San Diego Padres | Traded from Rangers to Padres to complete earlier trade | MLB |
| 2012-12-06 | Kyle Kaminska | Boston Red Sox | Traded from Pirates to Red Sox to complete an earlier deal | AAA |
| 2012-12-07 | Jeff Kobernus | Detroit Tigers | Traded from Red Sox to Tigers for Justin Henry | MLB |
| 2012-12-07 | Kyle Lobstein | Detroit Tigers | Traded from Mets to Tigers for cash considerations | MLB |
| 2012-12-07 | Graham Godfrey | Boston Red Sox | Traded from Athletics to Red Sox to complete earlier trade for Sandy Rosario on Nov 28 | MLB |
| 2012-12-09 | Lisalverto Bonilla | Texas Rangers | Traded from Philadelphia Phillies with Josh Lindblom to Texas for Michael Young | MLB |
| 2012-12-09 | James Shields | Kansas City Royals | Traded from Tampa Bay Rays with Wade Davis and Elliot Johnson to KC Royals for Wil Myers, Jake Odorizzi, Mike Montgomery and Patrick Leonard | MLB |
| 2012-12-09 | Wade Davis | Kansas City Royals | Traded from Tampa Bay Rays with James Shields and Elliot Johnson to KC Royals for Wil Myers, Jake Odorizzi, Mike Montgomery and Patrick Leonard | MLB |
| 2012-12-10 | Michael Young | Philadelphia Phillies | Traded from Rangers to Phillies for Josh Lindblom and Lisalverto Bonilla | MLB |
| 2012-12-10 | Josh Lindblom | Texas Rangers | Traded from Phillies with Lisalverto Bonilla to Rangers for Michael Young | MLB |
| 2012-12-10 | Lisalverto Bonilla | Texas Rangers | Traded from Phillies with Josh Lindblom to Rangers for Michael Young | MLB |
| 2012-12-10 | Wade Davis | Kansas City Royals | Traded from Rays with James Shields and PTNBL to Royals for Will Myers, Jake Odorizzi, Mike Montgomery and Patrick Leonard | MLB |
| 2012-12-10 | James Shields | Kansas City Royals | Traded from Rays with Wade Davis and PTNBL to Royals for Will Myers, Jake Odorizzi, Mike Montgomery and Patrick Leonard | MLB |
| 2012-12-10 | Wil Myers | Tampa Bay Rays | Traded from Royals with Jake Odorozzi, Mike Montgomery and Patrick Leonard to Rays for James Shields, Wade Davis and PTBNL | MLB |
| 2012-12-10 | Mike Montgomery | Tampa Bay Rays | Traded from Royals with Jake Odorozzi, Will Myers and Patrick Leonard to Rays for James Shields, Wade Davis and PTBNL | MLB |
| 2012-12-10 | Jake Odorizzi | Tampa Bay Rays | Traded from Royals with Will Myers, Mike Montgomery and Patrick Leonard to Rays for James Shields, Wade Davis and PTBNL | MLB |
| 2012-12-10 | Patrick Leonard | Tampa Bay Rays | Traded from Royals with Jake Odorozzi, Mike Montgomery and Will Myers to Rays for James Shields, Wade Davis and PTBNL | AAA |
| 2012-12-11 | Shin-Soo Choo | Cincinnati Reds | Traded from Indians with Jason Donald and cash to Reds for Drew Stubbs | MLB |
| 2012-12-11 | Jason Donald | Cincinnati Reds | Traded from Indians with Shin-Soo Choo and cash to Reds for Drew Stubbs | MLB |
| 2012-12-11 | Drew Stubbs | Cleveland Indians | Traded from Reds to Indians for Shin-Soo Choo, Jason Donald and cash | MLB |
| 2012-12-11 | Tony Sipp | Arizona Diamondbacks | Traded from Indians with Lars Anderson to Diamondbacks for Trevor Bauer, Matt Albers and Bryan Shaw | MLB |
| 2012-12-11 | Lars Anderson | Arizona Diamondbacks | Traded from Indians with Tony Sipp to Diamondbacks for Trevor Bauer, Matt Albers and Bryan Shaw | MLB |
| 2012-12-11 | Trevor Bauer | Cleveland Indians | Traded from Diamondbacks with Matt Albers and Bryan Shaw to Indians for Tony Sipp and Lars Anderson | MLB |
| 2012-12-11 | Matt Albers | Cleveland Indians | Traded from Diamondbacks with Trevor Bauer and Bryan Shaw to Indians for Tony Sipp and Lars Anderson | MLB |
| 2012-12-11 | Bryan Shaw | Cleveland Indians | Traded from Diamondbacks with Matt Albers and Trevor Bauer to Indians for Tony Sipp and Lars Anderson | MLB |
| 2012-12-11 | Didi Gregorius | Arizona Diamondbacks | Traded from Reds to Diamondbacks as part of a 3-team deal including Drew Stubbs and Trevor Bauer | MLB |
| 2012-12-12 | Skip Schumaker | Los Angeles Dodgers | Traded from Cardinals to Dodgers for Jake Lemmerman | MLB |
| 2012-12-12 | Jake Lemmerman | St. Louis Cardinals | Traded from Dodgers to Cardinals for Skip Schumaker | AAA |
| 2012-12-13 | Chris Rearick | San Diego Padres | Traded from Rays to Padres for Vince Belnome | MLB |
| 2012-12-13 | Vince Belnome | Tampa Bay Rays | Traded from Padres to Rays for Chris Rearick | MLB |
| 2012-12-17 | Ricky Martinez | Houston Astros | Traded from Cardinals to Astros for cash considerations | A+ |
| 2012-12-17 | R.A. Dickey | Toronto Blue Jays | Traded from Mets with Mike Nickeas and Josh Thole to Blue Jays for Travis d'Arnaud, Noah Syndergaard, John Buck and Wuilmer Becerra | MLB |
| 2012-12-17 | Mike Nickeas | Toronto Blue Jays | Traded from Mets with R.A. Dickey and Josh Thole to Blue Jays for Travis d'Arnaud, Noah Syndergaard, John Buck and Wuilmer Becerra | MLB |
| 2012-12-17 | Josh Thole | Toronto Blue Jays | Traded from Mets with R.A. Dickey and Mike Nickeas to Blue Jays for Travis d'Arnaud, Noah Syndergaard, John Buck and Wuilmer Becerra | MLB |
| 2012-12-17 | John Buck | New York Mets | Traded from Blue Jays with Travis d'Arnaud, Noah Syndergaard and Wuilmer Becerra to Mets for R.A. Dickey, Josh Thole and Mike Nickeas | MLB |
| 2012-12-17 | Travis d'Arnaud | New York Mets | Traded from Blue Jays with John Buck, Noah Syndergaard and Wuilmer Becerra to Mets for R.A. Dickey, Josh Thole and Mike Nickeas | MLB |
| 2012-12-17 | Noah Syndergaard | New York Mets | Traded from Blue Jays with John Buck, John Buck and Wuilmer Becerra to Mets for R.A. Dickey, Josh Thole and Mike Nickeas | MLB |
| 2012-12-17 | Wuilmer Becerra | New York Mets | Traded from Blue Jays with John Buck, John Buck and John Buck to Mets for R.A. Dickey, Josh Thole and Mike Nickeas | A+ |
| 2012-12-18 | Collin Cowgill | New York Mets | Traded from Athletics to Mets for Jefry Marte | MLB |
| 2012-12-18 | Jefry Marte | Oakland Athletics | Traded from Mets to Athletics for Collin Cowgill | MLB |
| 2012-12-19 | John Ely | Houston Astros | Traded from Dodgers to Astros for Rob Rasmussen | MLB |
| 2012-12-19 | Rob Rasmussen | Los Angeles Dodgers | Traded from Astros to Dodgers for John Ely | MLB |
| 2012-12-19 | Jason Vargas | Los Angeles Angels | Traded from Mariners to Angels for Kendry Morales | MLB |
| 2012-12-19 | Kendrys Morales | Seattle Mariners | Traded from Angels to Mariners for Jason Vargas | MLB |
| 2012-12-26 | Ivan De Jesus | Pittsburgh Pirates | Traded from Boston Red Sox with Mark Melancon, Stolmy Pimentel and Jerry Sands to Pittsburgh for Joel Hanrahan and Brock Holt | MLB |
| 2012-12-26 | Jerry Sands | Pittsburgh Pirates | Traded from Boston Red Sox with Mark Melancon, Ivan De Jesus and Stolmy Pimentel to Pittsburgh for Joel Hanrahan and Brock Holt | MLB |
| 2012-12-26 | Joel Hanrahan | Boston Red Sox | Traded from Pittsburgh Pirates with Brock Holt to Boston for Mark Melancon, Ivan De Jesus, Stolmy Pimentel and Jerry Sands | MLB |
| 2012-12-26 | Brock Holt | Boston Red Sox | Traded from Pittsburgh Pirates with Joel Hanrahan to Boston for Mark Melancon, Ivan De Jesus, Stolmy Pimentel and Jerry Sands | MLB |
| 2012-12-27 | Joel Hanrahan | Boston Red Sox | Traded from Pirates with Brock Holt to Red Sox for Mark Melancon, Stolmy Pimentel, Ivan DeJesus Jr. and Jerry Sands | MLB |
| 2012-12-27 | Brock Holt | Boston Red Sox | Traded from Pirates with Joel Hanrahan to Red Sox for Mark Melancon, Stolmy Pimentel, Ivan DeJesus Jr. and Jerry Sands | MLB |
| 2012-12-27 | Mark Melancon | Pittsburgh Pirates | Traded by Red Sox with Stolmy Pimentel, Ivan DeJesus Jr and Jerry Sands to Pirates for Joel Hanrahan and Brock Holt | MLB |
| 2012-12-27 | Jerry Sands | Pittsburgh Pirates | Traded by Red Sox with Stolmy Pimentel, Ivan DeJesus Jr and Mark Melancon to Pirates for Joel Hanrahan and Brock Holt | MLB |
| 2012-12-27 | Stolmy Pimentel | Pittsburgh Pirates | Traded by Red Sox with Mark Melancon, Ivan DeJesus Jr and Jerry Sands to Pirates for Joel Hanrahan and Brock Holt | MLB |
| 2012-12-27 | Sawyer Carroll | San Diego Padres | Traded by Blue Jays to Padres for cash considerations | AAA |
| 361 record(s) |