Ashleigh Barty defeated Karolína Plíšková in the final, 7–6(7–1), 6–3 to win the women's singles tennis title at the 2019 Miami Open.

She entered the top 10 in the WTA rankings for the first time with the win.

[1] Sloane Stephens was the defending champion, but lost in the third round to Tatjana Maria.

1 singles ranking after Simona Halep lost in the semifinals.

[3] Petra Kvitová, Angelique Kerber, and Elina Svitolina were also in contention for the top ranking.