The 1998–99 BBL season was the 12th season of the British Basketball League, known as the Budweiser Basketball League for sponsorship reasons, since its establishment in 1987. The regular season commenced on September 12, 1998, and ended on April 4, 1999, with a total of 13 teams competing, playing 36 games each. The post-season Play-offs began on April 9 and culminated in the end-of-season finale on May 2 at Wembley Arena. Start-up franchise Edinburgh Rocks became the League's newest member following their addition as the 14th franchise during the pre-season and the first Scottish team to appear in the top-flight since Glasgow Rangers' participation in the 1988–89 season. The League membership was reduced to 13 teams shortly after following the merger of the London Towers and Crystal Palace franchises, whilst another notable change was the uprooting of Watford Royals, who moved to the Bletchley Centre in Milton Keynes to become the Milton Keynes Lions. Sheffield Sharks were a dominant force throughout the season, winning the Sainsbury's Classic Cola Cup whilst storming the Budweiser League and taking the Championship to complete the "Double". The campaign came down to a memorable final game where Sharks claimed the title from rivals Manchester Giants with the last shot of the game, winning 85–87 to take the crown. Their successful run fell short in the play-offs however, managing only a third-placed finish thus allowing a new-look London Towers to claim the title. Manchester Giants also ended a decade-long drought of silverware with their win in the uni-ball Trophy. No teams participated in European competition after Birmingham Bullets and Greater London Leopards both declined to compete in the Saporta Cup.

Notable occurrences

Budweiser League Championship (Tier 1)

Final standings

Playoffs

Quarter-finals

(1) Sheffield Sharks vs. (8) Greater London Leopards (2) Manchester Giants vs. (7) Birmingham Bullets (3) London Towers vs. (5) Newcastle Eagles (4) Thames Valley Tigers vs. (6) Derby Storm

Semi-finals

Third-place game

Final

National League Division 1 (Tier 2)

Final standings

Champions by virtue of head-to-head record*

Playoffs

Quarter-finals Semi-finals Final

National League Division 2 (Tier 3)

Final standings

Playoffs

Quarter-finals Semi-finals Final

National League Division 3 (Tier 4)

Final standings

Playoffs

Quarter-finals Semi-finals Final

Sainsbury's Classic Cola National Cup

Last 16

Quarter-finals

Semi-finals

Final

uni-ball Trophy

Group stage

Group A Group B

Quarter-finals

Semi-finals

Derby Storm vs. Leicester Riders Sheffield Sharks vs. Manchester Giants

Final

Dairylea Dunkers All-Star Game

Statistics leaders

Seasonal awards