2018 Porsche Tennis Grand Prix – Singles
| Singles | |
|---|---|
| 2018 Porsche Tennis Grand Prix | |
| Champion | Karolína Plíšková |
| Runner-up | CoCo Vandeweghe |
| Score | 7–6(7–2), 6–4 |
| Draw | 28 |
| Seeds | 8 |
Laura Siegemund was the defending champion, but lost in the second round to CoCo Vandeweghe.
Karolína Plíšková won the title, defeating Vandeweghe in the final, 7–6(7–2), 6–4.
15-year-old Marta Kostyuk became the youngest player to win a main draw match in Stuttgart since Martina Hingis in October 1994.