This is a list of Major League Baseball replacement players. The Major League Baseball, an American and Canadian baseball league, has used replacement players during two strikes: the 1912 Detroit Tigers strike, and the 1994–95 Major League Baseball strike.

The following Major League Baseball players appeared as strikebreakers during spring training in 1995, crossing picket lines during the 1994–95 Major League Baseball strike. Some had not yet been placed on a 40-man roster, and as such were not eligible to join the MLBPA at the time of the strike, while others were former MLB players who had retired before the strike. The list does not include replacement players who never appeared in regular-season MLB games.

Certain players who were part of World Series-winning teams were not permitted to have their names or likenesses on commemorative merchandise because they had been declared replacement players for having participated in the 1995 spring training. The players were Shane Spencer of the 1998, 1999 and 2000 New York Yankees, Damian Miller of the 2001 Arizona Diamondbacks, Brendan Donnelly of the 2002 Anaheim Angels, and Brian Daubach and Kevin Millar of the 2004 Boston Red Sox.

The names or likenesses of replacement players, since they are not permitted to join the MLBPA, are also in some cases not included in merchandise which derives its license from the MLBPA, such as video and tabletop games. Many games nevertheless include them, with blank or fictional names and different appearances similar to how Jon Dowd was used to replace Barry Bonds in MVP Baseball 2005 after he left the MLBPA in 2003.

On May 15, 1912, Detroit Tigers star Ty Cobb went into the stands and assaulted a fan who had been heckling him. Cobb was suspended by American League President Ban Johnson. The other Tigers refused to play unless Cobb was reinstated. Johnson threatened Tigers owner Frank Navin with a stiff fine if he did not field a team. So Manager Hughie Jennings quickly recruited a pickup team of sandlot players, semi-pro players, and college baseball students.^[32]

This replacement team played one game, on May 18, 1912, after which the Tigers players relented and returned to play future games (under threat of lifetime banishment).^[33]

The following players appeared in the May 18, 1912 game,^[34] which the Tigers lost to the Philadelphia Athletics, 24–2.^[35]

Joe Sugden and Deacon McGuire were Tigers coaches who had had long baseball careers. This game was their last major league appearance. Hughie Jennings was the Tigers manager; he also had had a long career and was later elected to the Baseball Hall of Fame.^[36] Jennings appeared as pinch hitter in the ninth inning.^[34]

None of the other players ever appeared in another major league game before or after, except for Billy Maharg, who appeared in one other game^[36] as a courtesy in the last game of the 1916 season.^[37] Maharg was later deeply involved in the Black Sox Scandal.^[37] Jack Smith played two innings in the field, but had no plate appearances and consequently no batting average. Ed Irwin was the only recruit to have a hit (the Tigers coaches each had one). Irwin had two triples, and so retired with a major league batting average of .667 and slugging average of 2.000. Allan Travers's 24 runs allowed is still the American League record for a complete game.^[33][36]

Arthur "Bugs" Baer, who later went on to become a noted journalist and humorist, was a member of the team, recruited as a backup bench player. He did not appear in the game.^[32]