Updated to match(es) played on 8 June 1980. Source: NBL.com.au
The NBL tie-breaker system as outlined in the NBL Rules and Regulations states that in the case of an identical win–loss record, the results in games played between the teams will determine order of seeding.
1Head-to-Head between St. Kilda Saints and West Adelaide Bearcats (1-1). St. Kilda Saints won For and Against (+8).
2Illawarra Hawks won Head-to-Head (2-0).
3Head-to-Head between Coburg Giants and City of Sydney Astronauts (1-1). Coburg Giants won For and Against (+22).
The NBL finals series in 1980 consisted of two semifinal games, and one championship-deciding grand final. All three of these finals games were sudden death.