2021 Porsche Tennis Grand Prix – Singles

World No. 1 Ashleigh Barty defeated Aryna Sabalenka in the final, 3–6, 6–0, 6–3 to win the Women's Singles tennis title at the 2021 edition of the Stuttgart Open. Petra Kvitová was the defending champion from when the tournament was last held in 2019, but lost in the quarterfinals to Elina Svitolina.

2021 Porsche Tennis Grand Prix – Singles

World No. 1 Ashleigh Barty defeated Aryna Sabalenka in the final, 3–6, 6–0, 6–3 to win the Women's Singles tennis title at the 2021 edition of the Stuttgart Open. Petra Kvitová was the defending champion from when the tournament was last held in 2019, but lost in the quarterfinals to Elina Svitolina.