1978 New South Wales Open

The 1978 New South Wales Open, also known by its sponsored name Marlboro New South Wales Open, was a combined men's and women's tennis tournament played on outdoor grass courts at the White City Stadium in Sydney, Australia. The men's event was part of the 1978 Colgate-Palmolive Grand Prix circuit while the women's event was art of the 1979 Colgate Series. It was the 86th edition of the event and was held from 18 December through 24 December 1978. The singles titles were won by unseeded Tim Wilkison and second-seeded Dianne Fromholtz.

Men's singles
🇺🇸 Tim Wilkison defeated 🇳🇿 Kim Warwick 6–3, 6–3, 6–7, 3–6, 6–2

Women's singles
🇦🇺 Dianne Fromholtz defeated 🇦🇺 Wendy Turnbull 6–2, 7–5

Men's doubles
🇺🇸 Hank Pfister / 🇺🇸 Sherwood Stewart defeated 🇦🇺 Syd Ball / 🇦🇺 Bob Carmichael 6–4, 6–4

Women's doubles
🇦🇺 Lesley Hunt / 🇺🇸 Sharon Walsh defeated Ilana Kloss /  Marise Kruger 6–2, 6–1