The 2008–09 Euroleague was the 9th season of the professional basketball competition for elite clubs throughout Europe, organised by Euroleague Basketball Company, and it was the 52nd season of the premier competition for European men's clubs overall.

The season, which featured 24 teams from 13 countries, culminated in the 2008–09 Euroleague Final Four at the new O2 World arena in Berlin, Germany.

If two or more clubs finished level on won-lost record, tiebreakers were applied in the following order:[3] Games were played from October 22, 2008 to January 15, 2009.

Quarterfinals In the quarterfinals, the top placed teams from each Top 16 group played second placed teams from a different group in a best-of-five playoff series, with the winners of those series advancing to the Final Four.

The draw was conducted on January 19 at Euroleague Basketball Company headquarters in Barcelona.

*FC Barcelona wins the group over Real Madrid by the head-to-head point differential.