South Melbourne players, officials and supporters celebrate in Sydney as the club defeats Sydney Olympic 4-2 on aggregate to win its first ever NSL Championship in 1984.
| Season | League | Regular Season | Finals Series | Buffalo Cup | Dockerty Cup | National League Cup |
| 1980 | National League | 3rd (14 teams) |
– | Semi Final (0-1 v Melbourne Croatia) |
Semi Final (0-1 v Preston) |
Second Round (1-2 v Heidelberg) |
| 1981 | National League | 2nd (16 teams) |
– | – | – | First Round (0-2 v Heidelberg) |
| 1982 | National League | 6th (16 teams) |
– | Champions (2-1 v Heidelberg) |
– | First Round (0-0 [4-5p] v Heidelberg) |
| 1983 | National League | 4th (16 teams) |
– | Semi Final (0-2 v Green Gully) |
– | Semi Finalist (1-3 v Heidelberg) |
| 1984 | National League | Premiers (Southern Div) (12 teams) |
Southern Grand Final: 4-2 v Heidelberg United National Grand Final: 2-1 v Sydney Olympic (h) 2-1 v Sydney Olympic (a) Champions (4-2 agg) |
Champions (3-1 v Melbourne Croatia) |
– | Group Stage |
| 1985 | National League | Premiers (Southern Div) (12 teams) |
Southern Div Prelim Final (3-3 [4-5p] v Preston) |
Group Stage | Third Round (1-2 v Morwell Falcons) |
First Round (0-1 v Preston) |
| 1986 | National League | 7th (Southern Div) (12 teams) |
Missed finals | Group Stage | Third Round (2-3 v Caulfield City) |
Second Round (1-2 v Croydon City) |
| 1987 | National League | 6th (13 teams) |
– | Finalist (0-2 v Melbourne Croatia) |
Quarter Final (0-2 v Melbourne Croatia) |
Finalist (0-2 v Sydney Croatia) |
| 1988 | National League | 3rd (12 teams) |
Semi Final (1-2 v Marconi) |
Champions (3-1 v Preston) |
Champions* (3-4 v Melbourne Croatia) |
Semi Final (0-1 v Brunswick Juventus) |
| 1989 | National League | 8th (12 teams) |
Missed finals | Champions (3-0 v Melbourne JUST) |
– | Semi Final (0-2 v Adelaide City) |
* In 1988, SMFC were awarded the Dockerty Cup after Melbourne Croatia fielded an ineligible player