| Competition: | 1. divisjon |
| Season: | 1981 |
| Winners: | Vålerengen 2nd title |
| Relegated: | Brann Haugar Lyn |
| Continentalcup1: | European Cup |
| Continentalcup1 Qualifiers: | Vålerengen |
| Continentalcup2: | Cup Winners' Cup |
| Continentalcup2 Qualifiers: | Lillestrøm |
| Continentalcup3: | UEFA Cup |
| Continentalcup3 Qualifiers: | Viking |
| Matches: | 132 |
| Total Goals: | 367 |
| League Topscorer: | Pål Jacobsen (16 goals) |
| Biggest Home Win: | (23 August 1981) |
| Biggest Away Win: | (17 August 1981) |
| Highest Scoring: | (18 October 1981) |
| Longest Wins: | Brann Fredrikstad Rosenborg Viking Vålerengen (3 games) |
| Longest Unbeaten: | Fredrikstad Moss Rosenborg (9 games) |
| Longest Winless: | Haugar (9 games) |
| Longest Losses: | Brann HamKam Lyn (6 games) |
| Highest Attendance: | 21,377 (29 June 1981) |
| Lowest Attendance: | 1,085 (27 September 1981) |
| Average Attendance: | 5,880 15.6% |
| Dates: | 24 April – 18 October |
| Prevseason: | 1980 |
| Nextseason: | 1982 |
The 1981 1. divisjon was the 37th completed season of top division football in Norway.
22 games were played with 2 points given for wins and 1 for draws. Number eleven and twelve were relegated. The winners of the two groups of the Second Division were promoted, as well as the winner of a series of play-off matches between number ten in the 1. divisjon and the two second-placed teams in the two groups of the 2. divisjon.
Vålerengen won the championship, their second league title.
Note: Table lists in alphabetical order.
The qualification play-off matches were contested between Brann (10th in the 1. divisjon), Pors (2nd in the Second Division – Group A), and Molde (2nd in the 2. divisjon – Group B). Molde won on goal difference and were promoted to the 1. divisjon.
| Rank | Player | Club | Goals |
|---|---|---|---|
| 1 |  Pål Jacobsen | Vålerengen | 16 |
| 2 | Svein Mathisen | Start | 12 |
| 3 | Bernt Mæland | Bryne | 9 |
| Odd Iversen | Rosenborg | ||
| Vidar Hansen | Fredrikstad | ||
| Per Egil Ahlsen | Fredrikstad | ||
| Geir Henæs | Moss | ||
| 8 | Morten Haugen | Vålerengen | 7 |
| Ingvar Dalhaug | Brann | ||
| Peter Osborne | Haugar | ||
| Tor Arne Granerud | Ham-Kam | ||
| Kjell Ødegaard | Lyn |