| NSL Cup | |
| Year: | 1989–90 |
| Other Titles: | National Soccer League Cup |
| Country: | Australia |
| Num Teams: | 14 |
| Winners: | South Melbourne |
| Count: | 1 |
| Second: | Sydney Olympic |
| Matches: | 13 |
| Goals: | 47 |
| Scoring Leader: | Abbas Saad Kimon Taliadoros Paul Trimboli (3 each) |
| Prev Season: | 1989 |
| Next Season: | 1990–91 |
The 1989–90 NSL Cup was the 14th edition of the NSL Cup, which was the main national association football knockout cup competition in Australia.
Adelaide City were the defending champions, having defeated Sydney Olympic to win their second title in the previous year's final, but they were eliminated in the semi-finals by eventual winners South Melbourne.[1]
South Melbourne defeated Sydney Olympic 4–1 in the final to win their first NSL Cup title.[2]
The NSL Cup was a knockout competition with 14 teams taking part all trying to reach the Final in April 1990.[3] The competition consisted of the 14 teams from the National Soccer League.
| Round | Main date | Number of fixtures | Clubs remaining | |
|---|---|---|---|---|
| First round | Wednesday 14 February 1990 | 6 | 14 → 8 | |
| Second round | Wednesday 21 March 1990 | 4 | 8 → 4 | |
| Semi-finals | Wednesday 11 April 1990 | 2 | 4 → 2 | |
| Final | Wednesday 25 April 1990 | 1 | 2 → 1 |
APIA Leichhardt and Blacktown City had a bye for the First round.
See main article: 1990 NSL Cup final.