1970 US Open – Women's singles

Defending champion Margaret Court defeated Rosie Casals in the final, 6–2, 2–6, 6–1 to win the women's singles tennis title at the 1970 US Open. With the win, Court completed the Grand Slam, becoming the first woman in the Open Era to do so. It was her record-breaking 20th major singles title, surpassing Helen Wills Moody's all-time tally.

Seeds
• # 🇦🇺 Margaret Court (champion)

• # 🇺🇸 Rosie Casals (final)

• # 🇺🇸 Nancy Richey (semifinals)

• # 🇫🇷 Françoise Dürr (quarterfinals)

• # 🇬🇧 Virginia Wade (semifinals)

• # 🇦🇺 Kerry Melville (quarterfinals)

• # 🇦🇺 Karen Krantzcke (withdrew before the tournament began)

• # 🇦🇺 Judy Dalton (third round)