2018 Open Harmonie mutuelle

The 2018 Open Harmonie mutuelle was a professional tennis tournament played on hard courts. It was the fifteenth edition of the tournament which was part of the 2018 ATP Challenger Tour. It took place in Saint-Brieuc, France between 26 March and 1 April 2018.

Seeds

 * Rankings are as of 19 March 2018.

Other entrants
The following players received wildcards into the singles main draw:
 * 🇫🇷 Evan Furness
 * 🇫🇷 Manuel Guinard
 * 🇫🇷 Antoine Hoang
 * 🇫🇷 Ugo Humbert

The following players received entry into the singles main draw as special exempts:
 * 🇫🇷 Grégoire Barrère
 * 🇫🇷 Maxime Janvier

The following players received entry from the qualifying draw:
 * 🇧🇪 Joris De Loore
 * 🇱🇹 Laurynas Grigelis
 * 🇫🇷 Tristan Lamasine
 * 🇫🇷 Constant Lestienne

Singles

 * 🇱🇹 Ričardas Berankis def. 🇫🇷 Constant Lestienne 6–2, 5–7, 6–4.

Doubles

 * Sander Arends / 🇦🇹 Tristan-Samuel Weissborn def. 🇬🇧 Luke Bambridge / 🇬🇧 Joe Salisbury 4–6, 6–1, [10–7].