| Season | 2021 |
|---|---|
| Promoted | 18 teams |
← 2019 2022 → | |
The 2021 season of the 4. divisjon, the fifth highest association football league for men in Norway.
The league was consolidated: Oslo went from three to two groups, and Indre Østland's two groups were reduced in size.
Teams did not necessarily play each other home and away, because the first matchday was severely delayed due to the COVID-19 pandemic in Norway. In some districts, groups were made smaller to facilitate both home and away matches, whereas in larger groups the teams met only once.
Hordaland, Sogn og Fjordane and Trøndelag split their groups, doubling their respective number of groups, but with no more teams than before.
Sogn og Fjordane's two groups were unique in that every single team advanced to a playoff, where #1 from the two groups faced each other home and away, #2 from the two groups faced each other and so on.