The 2005–06 FIBA EuroCup was the 3rd season of the FIBA EuroCup, the third-strongest pan-European club basketball competition. It was the first season of the competition under the new name EuroCup which is now used for the formerly known ULEB Cup. A total number of 32 teams from 20 countries participated in competition. The season finished with the EuroCup Final Four, which was held in Kyiv, Ukraine. Joventut Badalona won the cup after defeating BC Khimki 88–63 in the final.
A number of 32 teams were split into 8 groups of four teams each. The top two teams in each group advanced to the next stage, where they were split into new four groups of four. The top two teams in each group in the second group stage advanced to the Quarter-Final, which was played in a Best-of-three playoff system. The winner of each series advanced to the 2006 EuroCup Final Four, which was held in Kyiv.
The number of the teams remained at 32 of which 7 were domestic champions (including Croatia) and 4 runners-up, including France and Israel.