The 2020–21 Derde Divisie season was the fifth edition of the Dutch fourth tier, formerly called Topklasse, since the restructuring of the league system in the summer of 2016.
[5] Later on 12 June, the KNVB officially announced that the Derde Divisie would again consist of 36 teams from next season.
The Hoofdklasse group leaders, namely Sportlust '46, Staphorst, Unitas and Hollandia, therefore moved up to the Derde Divisie.
The best runners-up of the Saturday and Sunday Hoofdklasse, Asser Christelijke Voetbalvereniging (ACV) and JOS Watergraafsmeer, were also promoted.
[7] On 24 February 2021, the KNVB eventually discontinued category A senior competitions in this season, including Derde Divisie, again without promotion or relegation.