[4] On 25 August 2020, guard Marko Gušić officially signed a four-year professional contract.

[5][6] On 8 September 2020, guards Dejan Davidovac and Ognjen Dobrić signed a two-year contract extensions.

[9] On 27 January 2021, center Johnny O'Bryant received a 10-day suspension from the club due to a conflict with head coach Dejan Radonjić during a game against Anadolu Efes.

[12] Reportedly, guards Corey Walden, Quino Colom, Langston Hall, and center Landry Nnoko as well as coaching staff members Nikola Birač, Saša Kosović, and Aleksandar Lukman were infected with the virus.

[19] On 23 February, guard Milutin Vujičić officially signed a four-year professional contract.

[20] On 24 February, Crvena zvezda signed professional contracts with two more teenagers from their youth system, center Filip Branković and guard Marko Mihailović.

[70] On 24 December 2020, head coach Obradović and the Zvezda parted ways by mutual consent.

[76] On 30 December, the Zvezda added two more assistant coaches to the staff, Goran Bošković and Miodrag Dinić.

[80][81] Crvena zvezda debuted their new Adidas uniforms for the 2019–20 season after unveiling on 6 September 2020, on the EuroLeague Media Day.

Crvena zvezda played at the 2020 Gloria Cup Basketball Tournament II in Antalya, Turkey which took place from 8–13 September.

Note: Originally to be scheduled to 20 December, due to the Crvena zvezda roster quarantine it was postponed[90] and rescheduled to 14 April 2021.

[91] Note: Originally to be scheduled to 10 January 2021, due to the Cibona roster quarantine it was postponed[92] and rescheduled to 16 March.

[95] Note: Originally to be scheduled to 7 February 2021, due to a large number of confirmed positive COVID-19 cases in Crvena zvezda mts team it was postponed,[96] and rescheduled to 20 April 2021.

Win Loss Note: Originally to be scheduled to 15 October, due to the ASVEL roster quarantine, it was moved to 11 November.