1978 US Open – Mixed doubles
| Mixed doubles | |
|---|---|
| 1978 US Open | |
| Champions | Frew McMillan Betty Stöve |
| Runners-up | Billie Jean King Ray Ruffels |
| Score | 6–3, 7–6 |
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.