1970 US Open – Mixed doubles
| Mixed doubles | |
|---|---|
| 1970 US Open | |
| Champions | Marty Riessen Margaret Court |
| Runners-up | Frew McMillan Judy Dalton |
| Score | 6–4, 6–4 |
| Draw | 34 |
| Seeds | 4 |
Marty Riessen and Margaret Court were the defending champions and successfully defended their title, defeating Frew McMillan and Judy Dalton 6–4, 6–4 in the final.
This was the first edition to feature a tie-break. It was used a sudden-death tie-break in all sets, winning the first to reach 5 points.