| Season: | 1975 |
| Competition: | 1. divisjon |
| Winners: | Viking 5th title |
| Relegated: | Skeid Vålerengen Os |
| Continentalcup1: | European Cup |
| Continentalcup1 Qualifiers: | Viking |
| Continentalcup2: | UEFA Cup |
| Continentalcup2 Qualifiers: | Brann Start |
| League Topscorer: | Arne Dokken (18 goals) |
| Matches: | 132 |
| Total Goals: | 336 |
| Biggest Home Win: | (8 May 1975) |
| Biggest Away Win: | (28 July 1975) |
| Highest Scoring: | (28 July 1975) |
| Longest Wins: | Mjøndalen (6 games) |
| Longest Unbeaten: | Brann (9 games) |
| Longest Winless: | Os (22 games) |
| Longest Losses: | Os (10 games) |
| Highest Attendance: | 16,516 (31 August 1975) |
| Lowest Attendance: | 1,183 (19 October 1975) |
| Average Attendance: | 6,772 17.8% |
| Dates: | 27 April – 19 October |
| Prevseason: | 1974 |
| Nextseason: | 1976 |
The 1975 1. divisjon was the 31st completed season of top division football in Norway.
It was contested by 12 teams, and Viking FK won the championship, their fourth consecutive league title and their fifth top-flight title overall.
Note: Table lists in alphabetical order.
Arne Dokken, Lillestrøm – 18 goals