1970 US Open – Mixed doubles

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.

Seeds
• # 🇺🇸 Marty Riessen / 🇦🇺 Margaret Court (champions)

• # Alex Metreveli / Olga Morozova (second round)

• # Frew McMillan / 🇦🇺 Judy Dalton (final)

• # 🇺🇸 Dennis Ralston / 🇫🇷 Françoise Dürr (semifinals)