| Norwegian Football Cup | |
| Year: | 1991 |
| Other Titles: | Norgesmesterskapet i fotball for herrer |
| Num Teams: | 128 (main competition) |
| Defending Champions: | Rosenborg |
| Winners: | Strømsgodset (4th title) |
| Second: | Rosenborg |
| Prev Season: | 1990 |
| Next Season: | 1992 |
The 1991 Norwegian Football Cup was the 86th edition of the Norwegian Football Cup. The final took place at Ullevaal Stadion in Oslo on 20 October 1991. Strømsgodset were won the Norwegian Cup after they defeated Rosenborg with the score 3–2. This was Strømsgodset's fourth Norwegian Cup title.
Below are the dates for each round as given by the official schedule:
| Round | Date(s) | Number of fixtures | width=100 | Clubs |
|---|---|---|---|---|
| 29–30 May 1991 | 64 | 128 → 64 | ||
| 11–12 June 1991 | 32 | 64 → 32 | ||
| 26 June 1991 | 16 | 32 → 16 | ||
| 24 July 1991 | 9 | 16 → 8 | ||
| 14 August 1991 | 5 | 8 → 4 | ||
| 14–15 September 1991 | 2 | 4 → 2 | ||
| Final | 20 October 1991 | 1 | 2 → 1 |
|colspan="3" style="background-color:#97DEFF"|29 May 1991|-|colspan="3" style="background-color:#97DEFF"|30 May 1991|-|colspan="3" style="background-color:#97DEFF"|2 June 1991|-|colspan="3" style="background-color:#97DEFF"|3 June 1991|}
|colspan="3" style="background-color:#97DEFF"|11 June 1991|-|colspan="3" style="background-color:#97DEFF"|12 June 1991|}
|colspan="3" style="background-color:#97DEFF"|25 June 1991|-|colspan="3" style="background-color:#97DEFF"|26 June 1991|-|colspan="3" style="background-color:#97DEFF"|27 June 1991|}
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See main article: 1991 Norwegian Football Cup final.