The 1981 NSL Cup was the fifth edition of the NSL Cup, which was the main national association football knockout cup competition in Australia.
Marconi Fairfield were the defending champions, having defeated Heidelberg United to win their first title in the previous year's final, but they were eliminated in the semi-finals by Brisbane Lions.
Brisbane Lions defeated West Adelaide 3–1 in the final to win their first NSL Cup title.
Teams The NSL Cup was a knockout competition with 36 teams taking part all trying to reach the Final in September 1981. The competition consisted of the 16 teams from the National Soccer League plus 20 teams from their respective top division state leagues.
Round Main date Number of fixtures Clubs remaining First round Sunday 22 March 1981 16 36 → 20 Second round Wednesday 6 May 1981 10 20 → 10 Third round Tuesday 16 June 1981 2 10 → 8 Quarter-finals Wednesday 17 June 1981 4 8 → 4 Semi-finals Wednesday 5 August 1981 2 4 → 2 Final Sunday 20 September 1981 1 2 → 1
First round
Second round
Third round
Quarter-finals
Semi-finals
Final
References