| Champ: |  Elina Svitolina |
| Runner: |  Simona Halep |
| Score: | 6–0, 6–4 |
| Draw: | 56 (8 / 5) |
| Seeds: | 16 |
See main article: 2018 Italian Open (tennis).
Defending champion Elina Svitolina defeated Simona Halep in a rematch of the previous year's final, 6–0, 6–4 to win the women's singles tennis title at the 2018 Italian Open.[1]
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 in the quarterfinals.
This tournament marked the retirement of former US Open finalist Roberta Vinci. She lost in the first round to Aleksandra Krunić.[2]
The top eight seeds received a bye into the second round.