The 1981 Norwegian Football Cup was the 76th edition of the Norwegian annual knockout football tournament. The Cup was won by Lillestrøm after beating Moss in the cup final with the score 3–1. This was Lillestrøm's third Norwegian Cup title.
First round
|colspan="3" style="background-color:#97DEFF"|26 May 1981
|colspan="3" style="background-color:#97DEFF"|27 May 1981
|colspan="3" style="background-color:#97DEFF"|28 May 1981
|colspan="3" style="background-color:#97DEFF"|2 June 1981
|colspan="3" style="background-color:#97DEFF"|3 June 1981
|colspan="3" style="background-color:#97DEFF"|4 June 1981
|colspan="3" style="background-color:#97DEFF"|10 June 1981
|colspan="3" style="background-color:#97DEFF"|Replay: 4 June 1981
|colspan="3" style="background-color:#97DEFF"|Replay: 8 June 1981
|colspan="3" style="background-color:#97DEFF"|Replay: 10 June 1981
|colspan="3" style="background-color:#97DEFF"|Replay: 11 June 1981
Second round
|colspan="3" style="background-color:#97DEFF"|23 June 1981
|colspan="3" style="background-color:#97DEFF"|24 June 1981
|colspan="3" style="background-color:#97DEFF"|25 June 1981
|colspan="3" style="background-color:#97DEFF"|Replay: 1 July 1981
|colspan="3" style="background-color:#97DEFF"|Replay: 2 July 1981
|colspan="3" style="background-color:#97DEFF"|Replay: 8 July 1981
Third round
|colspan="3" style="background-color:#97DEFF"|8 July 1981
|colspan="3" style="background-color:#97DEFF"|9 July 1981
|colspan="3" style="background-color:#97DEFF"|12 July 1981
Fourth round
Replay
Quarter-finals
Semi-finals
Final
References http://www.rsssf.no