The 1998–99 Australian Baseball League season was the 10th season of the original Australian Baseball League, contested between six teams representing state and regional capitals: Adelaide Giants, Gold Coast Cougars, Melbourne Monarchs, Melbourne Reds, Perth Heat and Sydney Storm.
The Adelaide Giants finished the season on top of the ladder but were knocked out in Semi-final 1 by the Sydney Storm.
All play-off games in the 1998–99 ABL season were held at the then-recently completed Sydney Showground,[1] which was to become the main venue for baseball at the 2000 Summer Olympics.
Only 6 of the 8 teams from the previous season returned, The Hunter Eagles and Brisbane Bandits were both unable to continue in the league due to increasing financial pressure.
During the regular season each team made use of an active roster of 22–24 men, with a maximum of 4 import players.