Petra Kvitová defeated Kiki Bertens in the final, 7–6(8–6), 4–6, 6–3 to win the women's singles tennis title at the 2018 Madrid Open. It was Kvitová's third Madrid Open title, and she became the first player to win three women's singles titles at the Madrid Open.
Halep and Caroline Wozniacki were in contention for the WTA no. 1 singles ranking at the beginning of the tournament. Halep retained the top ranking when Wozniacki lost to Bertens in the third round.[1]