2018 Western & Southern Open – Women's singles

Kiki Bertens defeated Simona Halep in the final, 2–6, 7–6^(8–6), 6–2 to win the women's singles tennis title at the 2018 Cincinnati Masters. She saved a championship point en route to her first hard court and Premier 5-level title, and defeated the world No. 2 and No. 1 players, in the second round and final, respectively. Bertens became the first Dutchwoman to win the title.

Garbiñe Muguruza was the defending champion, but lost in the second round to Lesia Tsurenko.