2020–21 Greek Basketball Cup

The 2020–21 Greek Basketball Cup was the 46th edition of Greek top-tier level professional domestic basketball cup competition. The previous winner of the cup was AEK. The cup competition started on 13 September 2020 and ended on 9 May 2021. Panathinaikos won the competition.

Format
The top six teams from the top-tier level Greek Basket League's 2019–20 season, gained an automatic bye to the 2020–21 Greek Cup quarterfinals. While the seven lower-placed teams from the 2019–20 Greek Basket League season also gained an automatic bye to the 2020–21 Greek Cup phase two, competing for two quarterfinals spots with phase one winners. All sixteen teams from the second-tier level Greek A2 Basket League's 2019–20 season will start from phase one, competing for one spot in phase two of the cup. All rounds were played under a single elimination format.