The labels in the parentheses show how each team qualified for the place of its starting round:[1]

A total of 70 Euroleague Basketball officials set to work on the 2020–21 season in EuroLeague and EuroCup:[36][37] 1 The match, originally scheduled for 13 October,[38] was postponed to 8 December[39] after positive COVID-19 tests on Zenit [40] following decision on 19 October by Euroleague on rescheduling games affected by positive tests.

[41] 2 The match, originally scheduled for 15 October,[38] was postponed to 23 November[42] after positive COVID-19 tests on Zenit[40] following decision on 19 October by Euroleague on rescheduling games affected by positive tests.

The four remaining teams play a single knockout round on Friday evening, with the two winners advancing to the championship game.

Between 100 and 7,500 socially-distanced fans, depending on the venue and country, were allowed into the arenas of CSKA, Zenit, Fenerbahçe, Khimki, Maccabi, Žalgiris, Valencia, Milan, Baskonia, ASVEL, ALBA and Crvena zvezda.