1989 NSL Cup
The 1989 NSL Cup was the 13th edition of the NSL Cup, which was the main national association football knockout cup competition in Australia.
APIA Leichhardt were the defending champions, having defeated South Melbourne to win their first title in the previous year's final, but they were eliminated in the semi-finals by Sydney Olympic.
Adelaide City defeated Sydney Olympic 2–0 in the final to win their second NSL Cup title.
Teams
The NSL Cup was a knockout competition with 14 teams taking part all trying to reach the Final in August 1989. The competition consisted of the 14 teams from the National Soccer League.| Round | Main date | Number of fixtures | Clubs remaining |
| First round | Thursday 23 March 1989 | 6 | 14 → 8 |
| Second round | Saturday 15 April 1989 | 4 | 8 → 4 |
| Semi-finals | Wednesday 19 July 1989 | 2 | 4 → 2 |
| Final | Sunday 20 August 1989 | 1 | 2 → 1 |