The 2020–21 King Cup, or The Custodian of the Two Holy Mosques Cup, is the 46th edition of the King Cup since its establishment in 1957. The tournament is scheduled to commence in December 2020 and is scheduled to conclude with the final in May 2021.
The number of teams was reduced from 64 to 16 as a result of the COVID-19 pandemic in Saudi Arabia. The competition was limited to the 16 teams participating in the 2020–21 Saudi Professional League.
Participating teams
A total of 16 teams participated in this season. All of which compete in the Pro league.
Round of 16
| Date | Venue | Host Team | Score | Away Team |
| 16 December 2020 | Damac FC | 1-2 Emilio Zelaya / Cedric Amissi, Leandre Tawamba | Al-Taawoun | |
| 16 December 2020 | Al-Qadsiah | 1-0 Hassan Alamiri | Al-Shabab | |
| 16 December 2020 | Al-Nassr | 2-0 Ayman Salem, Sami Al Naji | Al-Raed | |
| 17 December 2020 | Al-Batin | 3-0 Renato Chaves, Zakaria Al Sudani,Fabio Abreu | Abha | |
| 17 December 2020 | Al-Ettifag | 0-0 (8-9 pen.) | Al-Faisaly | |
| 17 December 2020 | Al-Hilal | 0-2 Mourad Batna, Sofiane Bendebka | Al-Fateh | |
| 17 December 2020 | Al-Wehda | 0-3 Aleksandar Prijovic (2), Pedro Henrique (og) | Al-Ittihad | |
| 17 December 2020 | Al-Ahli | 0-2 Getterson, Filip Bradaric | Al-Ain |