| Competition: | 1. divisjon |
| Season: | 1986 |
| Relegated: | Viking Strømmen |
| Winners: | Lillestrøm 4th title |
| Continentalcup1 Qualifiers: | Lillestrøm |
| Continentalcup1: | European Cup |
| Continentalcup2 Qualifiers: | Mjøndalen |
| Continentalcup2: | UEFA Cup |
| Continentalcup3 Qualifiers: | Tromsø |
| Continentalcup3: | Cup Winners' Cup |
| Matches: | 132 |
| Total Goals: | 352 |
| Highest Scoring: | Viking 6–4 Ham-Kam[1] (7 September 1986) |
| Biggest Home Win: | (7 June 1986) Viking 4–0 Strømmen (5 October 1986) Start 6–2 Tromsø (19 October 1986) |
| Biggest Away Win: | Molde 0–4 Start (4 May 1986) |
| League Topscorer: | Arve Seland (12 goals) |
| Highest Attendance: | 28,569 (16 May 1986) |
| Lowest Attendance: | 202 (19 October 1986) |
| Average Attendance: | 3,261 24.3% |
| Dates: | 27 April – 19 October |
| Prevseason: | 1985 |
| Nextseason: | 1987 |
The 1986 1. divisjon was the 42nd completed season of top division football in Norway. The season began on 27 April 1986 and ended on 19 October 1986.
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 2. divisjon were promoted, as well as the winner of a series of play-off matches between the two second-placed teams in the two groups of the 2. divisjon and number ten in the 1. divisjon.
Lillestrøm SK won the league, after a slow start but later 11 consecutive wins. It was Lillestrøm's fourth title. Viking and Strømmen were relegated to the 2. divisjon. The league had low attendances this year.[2]
Note: Table lists in alphabetical order.
The qualification matches were contested between Tromsø (10th in the 1. divisjon), Drøbak/Frogn (2nd in the 2. divisjon - Group A), and Vidar (2nd in the 2. divisjon - Group B). Tromsø won and remained in the 1. divisjon.
| Rank | Player | Club | Goals |
|---|---|---|---|
| 1 |  Arve Seland | Start | 12 |
| 2 | Freddy Ørbeck | Mjøndalen | 11 |
| 3 | Arne Larsen Økland | Bryne | 10 |
| 4 | Paul Folkvord | Bryne | 9 |
| Sten Glenn Håberg | Lillestrøm | ||
| Odd Johnsen | Mjøndalen | ||
| 7 | Paal Fredheim | Vålerengen | 8 |
| 8 | Sverre Brandhaug | Rosenborg | 7 |
| Jan Åge Fjørtoft | Ham-Kam | ||
| Egil Johansen | Vålerengen | ||
| Tore Kallstad | Strømmen |