The 2003–04 BBL season was the 17th campaign in the history of the British Basketball League.
This season saw the first edition of the newly created Haribo Cup.
Following the BBL's decision to withdraw from the National Cup due to import player regulations, the League's newest competition saw all 10 teams competing in a knock-out style tournament culminating in the Grand Final at the National Indoor Arena in Birmingham.
Due to the lack of teams competing in this season's Championship, the BBL Trophy featured all 10 BBL teams plus two invited teams from the English Basketball League (Plymouth Raiders and Teesside Mohawks).
The First round saw all 12 teams divided into four regionalised groups with the top finishing team advancing to the Semi-finals.