The 1998 Eastern League season began on approximately April 1 and the regular season ended on approximately September 1.
The Harrisburg Senators defeated the New Britain Rock Cats 3 games to 1 to win the Eastern League Championship Series.
- Green shade indicates that team advanced to the playoffs
- Bold indicates that team advanced to ELCS
- Italics indicates that team won ELCS
Statistical league leaders
The New Britain Rock Cats defeated the Binghamton Mets in the Northern Division playoffs 3 games to 1.
The Harrisburg Senators defeated the Akron Aeros in the Southern Division playoffs 3 games to 1.
The Harrisburg Senators defeated the New Britain Rock Cats in the ELCS 3 games to 1.