| Singles | |
|---|---|
| 2018 Open BNP Paribas Banque de Bretagne | |
| Champion |  Quentin Halys |
| Runner-up |  Alexey Vatutin |
| Final score | 6–3, 7–6(7–1) |
Adrian Mannarino was the defending champion but chose not to defend his title.
Quentin Halys won the title after defeating Alexey Vatutin 6–3, 7–6(7–1) in the final.
Stefanos Tsitsipas (semifinals) Mikhail Youzhny (withdrew)
Mirza Bašić (second round)
Dustin Brown (second round) Quentin Halys (champion)
Martin Kližan (second round)
Uladzimir Ignatik (second round) Yannick Maden (second round)| Semifinals | Final | ||||||||||||
| 1/WC | Stefanos Tsitsipas | 6 | 4 | 64 | |||||||||
| 5 | Quentin Halys | 1 | 6 | 77 | |||||||||
| 5 | Quentin Halys | 6 | 77 | ||||||||||
| Alexey Vatutin | 3 | 61 | |||||||||||
| Alexey Vatutin | 6 | 77 | |||||||||||
| Calvin Hemery | 4 | 65 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1/WC | S Tsitsipas | 6 | 6 | ||||||||||||||||||||||||
| A Šetkić | 3 | 4 | 1/WC | S Tsitsipas | 6 | 5 | 6 | ||||||||||||||||||||
| SE | A Hoang | 6 | 6 | SE | A Hoang | 4 | 7 | 4 | |||||||||||||||||||
| J Kovalík | 3 | 4 | 1/WC | S Tsitsipas | 4 | 710 | 6 | ||||||||||||||||||||
 C Taberner | 4 | 1 |  S Napolitano | 6 | 68 | 4 | |||||||||||||||||||||
| S Napolitano | 6 | 6 | S Napolitano | 3 | 710 | 6 | |||||||||||||||||||||
| WC | E Furness | 4 | 6 | 3 | 8 | Y Maden | 6 | 68 | 2 | ||||||||||||||||||
| 8 | Y Maden | 6 | 4 | 6 | 1/WC | S Tsitsipas | 6 | 4 | 64 | ||||||||||||||||||
| 4 | D Brown | 6 | 6 | 5 | Q Halys | 1 | 6 | 77 | |||||||||||||||||||
| Alt |  J Clarke | 4 | 4 | 4 | D Brown | 3 | 77 | 2 | |||||||||||||||||||
| Q | M Janvier | 3 | 6 | 6 | Q | M Janvier | 6 | 64 | 6 | ||||||||||||||||||
| LL | Jeremy Jahn | 6 | 1 | 4 | Q | M Janvier | 64 | 2 | |||||||||||||||||||
 A De Greef | 2 | 4 | 5 | Q Halys | 77 | 6 | |||||||||||||||||||||
| V Millot | 6 | 6 | V Millot | 2 | 1 | ||||||||||||||||||||||
| M Bourgue | 3 | 4 | 5 | Q Halys | 6 | 6 | |||||||||||||||||||||
| 5 | Q Halys | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 6 | M Kližan | 65 | 6 | 6 | |||||||||||||||||||||||
| Q | D Guez | 77 | 2 | 4 | 6 | M Kližan | 6 | 4 | 65 | ||||||||||||||||||
| Q | G Barrère | 5 | 6 | 5 | LL | T Lamasine | 3 | 6 | 77 | ||||||||||||||||||
| LL | T Lamasine | 7 | 4 | 7 | LL | T Lamasine | 2 | 2 | |||||||||||||||||||
| A Vatutin | 6 | 6 | A Vatutin | 6 | 6 | ||||||||||||||||||||||
| WC | E Benchetrit | 1 | 1 | A Vatutin | 6 | 3 | 78 | ||||||||||||||||||||
| T Gabashvili | 6 | 1 | 2r | 3 | M Bašić | 3 | 6 | 66 | |||||||||||||||||||
| 3 | M Bašić | 4 | 6 | 5 | A Vatutin | 6 | 77 | ||||||||||||||||||||
| 7 | U Ignatik | 6 | 4 | 6 | C Hemery | 4 | 65 | ||||||||||||||||||||
| G Sakharov | 3 | 6 | 1 | 7 | U Ignatik | 4 | 4 | ||||||||||||||||||||
| C Hemery | 6 | 6 | C Hemery | 6 | 6 | ||||||||||||||||||||||
| A Arnaboldi | 4 | 4 | C Hemery | 6 | 6 | ||||||||||||||||||||||
| R Ojeda Lara | 0 | 6 | 3 | J Munar | 4 | 0 | |||||||||||||||||||||
| J Munar | 6 | 4 | 6 | J Munar | 66 | 77 | 6 | ||||||||||||||||||||
 M Trungelliti | 77 | 6 | M Trungelliti | 78 | 65 | 3 | |||||||||||||||||||||
| Q | M Donati | 64 | 1 | ||||||||||||||||||||||||
Nick Kyrgios was the defending champion. However, he did not defend the title after turning 18 and joining the ATP.
Alexander Zverev won the title, defeating Stefan Kozlov in the final, 6–3, 6–0.
Borna Ćorić was the defending champion, having won the event in 2013, but elevated to Men's Singles instead as a qualifier.
Ernests Gulbis was the defending champion, but lost to Dominic Thiem in the quarterfinals.
Thiem went on to win his first ATP title, defeating Leonardo Mayer in the final, 6–7(8–10), 7–5, 7–6(7–2).
John Millman was the defending champion but chose not to defend his title.
Alexandre Sidorenko was the defending champion but chose not to defend his title.
Quentin Halys was the defending champion but chose not to defend his title.
Jordan Thompson was the defending champion but lost in the quarterfinals to Quentin Halys.
Nick Kyrgios was the defending champion, but withdrew before the tournament began.
Ivo Karlović was the defending champion, but lost in the first round to Quentin Halys.
Richard Gasquet was the defending champion but withdrew before the tournament began.
Jürgen Melzer was the defending champion but chose not to defend his title.
Jo-Wilfried Tsonga was the defending champion, but withdrew before the tournament began.
Andy Murray was the defending champion, but could not participate this year as he was recovering from hip surgery.
Hiroki Moriya was the defending champion but chose not to defend his title.
Malek Jaziri was the defending champion but chose not to defend his title.
Lucas Pouille was the defending champion, but lost in the second round to Marcos Baghdatis.
Steve Johnson was the defending champion, but lost in the first round to Christopher Eubanks.
Ilya Ivashka was the defending champion but chose not to defend his title.
Jack Draper was the defending champion but lost in the first round to Borna Gojo.
Radu Albot was the defending champion but lost in the second round to Antoine Escoffier.