|Replaced by||Double-A Northeast|
|No. of teams||12|
|Trenton Thunder (2019)|
|Most titles||Binghamton Triplets (10)|
The Eastern League (EL) was a Minor League Baseball (MiLB) sports league that operated under that name from 1938 until early 2021, when it ceased operation due to a reorganization of the minor leagues by Major League Baseball. The league played at the Double-A level in 1963 and later, and consisted primarily of teams located in the Northeastern United States.
The league was founded in 1923 as the New York-Pennsylvania League. The first team outside the two original states was created in 1936 when the York White Roses of York, Pennsylvania, moved to Trenton, New Jersey, and were renamed the Trenton Senators. The league was renamed as the Eastern League in 1938 when the Scranton Miners of Scranton, Pennsylvania, moved to Hartford, Connecticut, and became the Hartford Bees.
From 1923 until ceasing operation, the league had teams in a total of 52 different cities, located in 12 different states and two Canadian provinces. The league consisted of six to eight teams from 1923 until 1993. The league expanded to 10 teams in 1994 with the addition of the Portland Sea Dogs and the New Haven Ravens and split into two divisions, the Northern Division and the Southern Division. The league expanded to 12 teams in 1999 with the addition of the Altoona Curve and the Erie SeaWolves. The two divisions were restructured and renamed for the 2010 season as the Eastern Division and the Western Division because the Connecticut Defenders moved to Richmond, Virginia, after the 2009 season, becoming the Richmond Flying Squirrels.
In early 2021, it was announced that 11 out of the 12 Eastern League teams would become part of Double-A Northeast, a replacement league for the Eastern League that is under the jurisdiction of Major League Baseball (MLB) as part of its new version of Minor League Baseball at the start of the 2021 season. The Trenton Thunder, which has been in the Eastern League since its establishment in 1980 as the Glens Falls White Sox and under its current name since 1994, was the only Eastern League team not accepted into the new Double-A Northeast league and the new version of Minor League Baseball; the Trenton Thunder switched to collegiate summer baseball and joined the new MLB Draft League, Major League Baseball's new top collegiate summer baseball league.
|Division||Team||MLB Affiliation||City||Stadium||Capacity||2021 League|
|Eastern||Binghamton Rumble Ponies||New York Mets||Binghamton, New York||NYSEG Stadium||6,012||Double-A Northeast|
|Hartford Yard Goats||Colorado Rockies||Hartford, Connecticut||Dunkin' Donuts Park||6,121||Double-A Northeast|
|New Hampshire Fisher Cats||Toronto Blue Jays||Manchester, New Hampshire||Northeast Delta Dental Stadium||6,500||Double-A Northeast|
|Portland Sea Dogs||Boston Red Sox||Portland, Maine||Hadlock Field||7,368||Double-A Northeast|
|Reading Fightin Phils||Philadelphia Phillies||Reading, Pennsylvania||FirstEnergy Stadium||10,000||Double-A Northeast|
|Trenton Thunder||New York Yankees||Trenton, New Jersey||Arm & Hammer Park||6,341||MLB Draft League |
|Western||Akron RubberDucks||Cleveland Indians||Akron, Ohio||Canal Park||7,630||Double-A Northeast|
|Altoona Curve||Pittsburgh Pirates||Altoona, Pennsylvania||Peoples Natural Gas Field||7,210||Double-A Northeast|
|Bowie Baysox||Baltimore Orioles||Bowie, Maryland||Prince George's Stadium||10,000||Double-A Northeast|
|Erie SeaWolves||Detroit Tigers||Erie, Pennsylvania||UPMC Park||6,000||Double-A Northeast|
|Harrisburg Senators||Washington Nationals||Harrisburg, Pennsylvania||FNB Field||6,187||Double-A Northeast|
|Richmond Flying Squirrels||San Francisco Giants||Richmond, Virginia||The Diamond||9,560||Double-A Northeast|
Notes: This list includes teams in predecessor New York-Pennsylvania League of 1923 to 1937.
Bold font indicates the final teams that played in the Eastern League's last season of operation.
A "^" indicates that team's article redirects to an article of an active team formerly of the Eastern League.
A "+" indicates that team's article redirects to an article of a defunct Eastern League team.
League champions have been determined by different means since the Eastern League's formation in 1923. Before 1934, the champions were simply the league pennant winners. A formal playoff system to determine league champions was established in 1934.
The Binghamton Triplets won 10 championships, the most among all teams in the league, followed by the Elmira Colonels/Pioneers/Royals (8) and the Scranton Miners/Red Sox (7). Among active franchises, the Harrisburg Senators have won 6 championships, the most in the league, followed by the Akron Aeros/RubberDucks (5) and Reading Fightin Phils (4).