2021 Norwegian Second Division
The 2021 Norwegian Second Division was a Norwegian football third-tier league season. The league consisted of 28 teams divided into 2 groups of 14 teams.
The league was played as a double round-robin tournament, where all teams played 26 matches. The season started on 19 June 2021 and concluded on 14 November 2021.
Kongsvinger earned promotion from group 1 on 23 October 2021, three rounds before the end of the season. Skeid secured promotion from group 2 on 6 November 2021, following a 12–0 win against Rosenborg 2.
Team changes
The following teams changed division since the 2020 season.To 2. divisjon
;Relegated from 1. divisjonFrom 2. divisjon
;Promoted to 1. divisjonGroup 1
Teams
The following 14 clubs compete in group 1:| Club | Location | Stadium | Capacity |
| Alta | Alta | Finnmarkshallen | 1,200 |
| Asker | Asker | Føyka Stadion | 2,400 |
| Brattvåg | Brattvåg | Brattvåg Stadion | 1,500 |
| Bærum | Bærum | Sandvika Stadion | 1,500 |
| Eidsvold Turn | Eidsvoll | Myhrer Stadion | 1,500 |
| Florø | Florø | Florø Stadion | 2,800 |
| Fløya | Tromsø | Fløya Arena | 1,500 |
| Hødd | Ulsteinvik | Nye Høddvoll | 4,081 |
| Kongsvinger | Kongsvinger | Gjemselund Stadion | 5,824 |
| Kvik Halden | Halden | Halden Stadion | 4,200 |
| Moss | Moss | Melløs Stadion | 4,000 |
| Senja | Silsand | Senja Stadion | 1,500 |
| Tromsdalen | Tromsø | TUIL Arena | 3,000 |
| Vålerenga 2 | Oslo | Intility Arena | 16,555 |
League table
Group 2
Teams
The following 14 clubs compete in group 2:| Club | Location | Stadium | Capacity |
| Arendal | Arendal | Norac Stadion | 5,000 |
| Egersund | Egersund | Idrettsparken | 2,000 |
| Fløy | Flekkerøy | Arkicon Arena | 2,000 |
| Fram Larvik | Larvik | Framparken | 2,500 |
| Kjelsås | Oslo | Grefsen Stadion | 2,000 |
| Levanger | Levanger | TOBB Arena | 2,200 |
| Nardo | Trondheim | Nissekollen Idrettspark | 1,800 |
| Notodden | Notodden | Optime Arena | 4,000 |
| Odd 2 | Skien | Skagerak Arena | 11,767 |
| Rosenborg 2 | Trondheim | SalMar Banen | 1,000 |
| Skeid | Oslo | Nordre Åsen Kunstgress | 2,500 |
| Sotra | Sotra | Straume Stadion | 1,200 |
| Vard Haugesund | Haugesund | Haugesund Sparebank Arena | 8,754 |
| Øygarden | Ågotnes | Ågotnes Stadion | 1,200 |
League table
Promotion play-offs
The teams who finished in second place in their respective group qualified for the promotion play-offs, where they faced each other over two legs. The winner went on to play against the 14th-placed team in the First Division for a place in the First Division next season.''Hødd won 4–3 on aggregate.''