1978 US Open – Mixed doubles

Frew McMillan and Betty Stöve were the defending champions and successfully defended their title, defeating Billie Jean King and Ray Ruffels in the final, 6–3, 7–6.

Seeds
• # Frew McMillan / Betty Stöve (champions)

• # 🇦🇺 Ray Ruffels / 🇺🇸 Billie Jean King (final)

• # 🇦🇺 Bob Hewitt / 🇦🇺 Wendy Turnbull (semifinals)

• # 🇦🇺 Chris Kachel / Ilana Kloss (third round)