The 2008–09 FIBA EuroChallenge was the sixth edition of Europe’s third-tier level transnational men’s professional club basketballFIBA EuroChallenge Tournament, and the first under the FIBA EuroChallenge name, organized by FIBA Europe. A total number of 32 teams participated in the regular season and a total of 40 teams competed including the qualifying rounds. Virtus Bologna won its first EuroChallenge title after defeating Cholet in the Final of the Final Four, which was hosted in Bologna.
In all there are 40 teams from 21 countries, plus sixteen teams from the 2008–09 Eurocup Basketball first preliminary round and second preliminary round. The competition is jointly run by FIBA Europe.
The labels in the parentheses show how each team qualified for the place of its starting round (TH: title holders;):
- 1st, 2nd, 3rd, 4th, 5th, etc.: League position after eventual Playoffs
- EC: Transferred from Eurocup
QR: Losers from qualifying rounds
- WC: Wild card