Which woman won US Open singles titles on both clay and hardcourt?

Chris Evert won US Open singles titles on both clay and hardcourt.

Evert won the final three US Opens played on clay, taking the title in 1975, 1976 and 1977. When the tournament moved to hard courts in 1978, she immediately won again, defeating Pam Shriver in the final. That made Evert the only woman to win the US Open singles event on both of those surfaces.

Her six US Open titles came in 1975–1978, 1980 and 1982. Evert was especially dominant on clay, but her 1978 victory showed that her game translated successfully to the faster hard courts used at the new Flushing Meadows site.

The wording can cause a different kind of confusion: Steffi Graf and Serena Williams also won major singles titles on multiple surfaces, but not the US Open on both clay and hardcourt. Martina Navratilova won US Open titles on hard courts, not during the tournament’s short clay period.