1978 Australian Open – Men's singles
Guillermo Vilas defeated John Marks in the final, 6–4, 6–4, 3–6, 6–3 to win the men's singles tennis title at the 1978 Australian Open. Vitas Gerulaitis was the defending champion, but did not compete this year. This tournament was the final Grand Slam tournament appearance for former four-time champion Ken Rosewall. Seeds. The seeded players are listed below. Guillermo Vilas is the champion; others show the round in which they were eliminated.