The American League East is one of Major League Baseball's six divisions. MLB consists of an East, Central, and West division for each of its two 15-team leagues, the American League (AL) and National League (NL). This division was created before the start of the 1969 season along with the American League West. Before that time, each league consisted of 10 teams without any divisions.

Four of the division's five teams are located in the Eastern United States, with the other team, the Toronto Blue Jays, in Eastern Canada. It is currently the only division that contains a non-American team. At the end of the Major League Baseball season, the team with the best record in the division earns one of the AL's six playoff spots.

Baseball writers have long posited that the American League East is the toughest division in MLB; during its 50-year existence, an AL East team has gone on to play in the World Series 28 times, and 16 of those teams have been crowned World Series champions. Since the 1995 season, when the wild-card playoff berth was introduced, the AL East has produced 20 of the 32 wild-card teams for the American League, with the AL West sending seven teams, and only five coming from the AL Central.

When MLB split into divisions for the 1969 season, the American League, unlike the National League, split its 12 teams strictly on geography. The six teams then located in the Eastern Time Zone were all placed in the AL East, with the other six teams making up the AL West.

In September 1971, American League owners approved the move of the second Washington Senators franchise to Arlington, Texas, to become the Texas Rangers. With the Rangers moving to the AL West, the owners then debated whether the Chicago White Sox or Milwaukee Brewers should move to the AL East for 1972. The White Sox requested they be moved to the East under the argument of being an original AL franchise and playing most of their longtime rival teams, of which five were in the East.

The Oakland Athletics (formerly from Kansas City and Philadelphia) objected to moving the White Sox to the East; owner Charlie Finley was a Chicago native who wanted to continue to make three trips per season with his club to the Second City. The Minnesota Twins went a step further and objected to switching either the White Sox or Brewers out of fear of losing their closest geographic rivals and the Twins, citing the National League's lack of geographic accuracy (which placed the Atlanta Braves in the NL West) in forming its divisions as a reason why the Rangers should not have been shifted out of the East. The Twins also argued that the National Football League's Dallas Cowboys played (and still do play) in the NFC East despite being far from the Northeast.

The White Sox' pleas notwithstanding, the Brewers, who began as the Seattle Pilots in 1969 and had to endure long divisional road trips to Oakland and Anaheim (and vice-versa) in the AL West, were moved to the AL East.

* – The Yankees and Red Sox finished with exact records, tied for the division championship; the Yankees won a one-game tie-breaker.