1990 Eastern League season

The 1990 Eastern League season began on approximately April 1 and the regular season ended on approximately September 1.

The London Tigers defeated the New Britain Red Sox three games to zero to win the Eastern League Championship Series.

Standings
Notes:
 * Green shade indicates that team advanced to the playoffs
 * Bold indicates that team advanced to ELCS
 * Italics indicates that team won ELCS

Semi-finals Series

 * London Tigers defeated the Canton–Akron Indians 3 games to 2.
 * New Britain Red Sox defeated the Albany/Colonie Yankees 3 games to 2.

Championship Series

 * London Tigers defeated the New Britain Red Sox 3 games to 0.