1978 Australian Open
Date	25 December – 3 January 1979
Edition	67th
Category	Grand Slam (ITF)
Surface	Grass
Location	Melbourne, Victoria, Australia
Venue	Kooyong Lawn Tennis Club
Champions
Men's singles
Guillermo Vilas[1]
Women's singles
Chris O'Neil[2]
Men's doubles
Wojciech Fibak / Kim Warwick[3]
Women's doubles
Betsy Nagelsen / Renáta Tomanová[4]
← 1977 · Australian Open · 1979 →

The 1978 Australian Open was a tennis tournament played on outdoor grass courts at the Kooyong Lawn Tennis Club in Melbourne, Australia and was held from 25 December 1978 to 3 January 1979. It was the 67th edition of the Australian Open and the fourth Grand Slam tournament of the year. The singles titles were won by Argentinian Guillermo Vilas and Australian Chris O'Neil.

Seniors

Men's singles

Guillermo Vilas defeated John Marks, 6–4, 6–4, 3–6, 6–3 ^[1]

• It was Vilas' 3rd career Grand Slam singles title and his 1st title at the Australian Open.

Women's singles

Chris O'Neil defeated Betsy Nagelsen, 6–3, 7–6^{(7–3) [2]}

• It was O'Neil's 1st and only career Grand Slam singles title.

Men's doubles

Wojciech Fibak / Kim Warwick defeated Paul Kronk / Cliff Letcher, 7–6, 7–5 ^[3]

• It was Fibak's only career Grand Slam doubles title.

• It was Warwick's 1st career Grand Slam doubles title.

Women's doubles

Betsy Nagelsen / Renáta Tomanová defeated Naoko Sato / Pam Whytcross, 7–5, 6–2 ^[4]

• It was Nagelsen's 1st career Grand Slam doubles title.

• It was Tomanová's 1st and only career Grand Slam doubles title.

Mixed doubles

This event was not held from 1970 until 1985.