In addition to the domestic league, Arminia Bielefeld participated in this season's edition of the DFB-Pokal.

In March, the manager Uwe Neuhaus was replaced by Frank Kramer.

A 2–0 win over VfB Stuttgart on the final matchday secured the 15th rank and thus their spot in the 2021–22 Bundesliga.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.