| Champ: |  Dominic Thiem |
| Runner: |  Gilles Simon |
| Score: | 3–6, 7–6(7–2), 6–1 |
| Draw: | 28 (4 / 3) |
| Seeds: | 8 |
| Edition: | 2nd |
| Type: | singles doubles |
| Main Name: | ATP Lyon Open |
See main article: 2018 ATP Lyon Open.
Jo-Wilfried Tsonga was the defending champion, but due to injury did not defend his title.
Dominic Thiem won the title, defeating Gilles Simon in the final, 3–6, 7–6(7–2), 6–1.
The top four seeds receive a bye into the second round.