| Date: | 25–31 March |
| Edition: | 16th |
| Surface: | Hard (indoor) |
| Location: | Saint-Brieuc, France |
| Champs: |  Kamil Majchrzak |
| Champd: |  Jonathan Erlich /  Fabrice Martin |
| After Year: | 2022 |
The 2019 Open Harmonie mutuelle was a professional tennis tournament played on hard courts. It was the sixteenth edition of the tournament which was part of the 2019 ATP Challenger Tour. It took place in Saint-Brieuc, France between 25 and 31 March 2019.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Lithuania | Ričardas Berankis | 82 | 1 | |
| France | Grégoire Barrère | 120 | 3 | |
 Russian Federation | Evgeny Donskoy | 126 | 4 | |
 Italy | Stefano Travaglia | 132 | 5 | |
| France | Corentin Moutet | 136 | 6 | |
| France | Antoine Hoang | 137 | 7 | |
| Poland | Kamil Majchrzak | 154 | 8 | |
 Austria | Dennis Novak | 156 | 9 | |
 Estonia | Jürgen Zopp | 159 | 10 | |
| France | Quentin Halys | 163 | 11 | |
 Bosnia and Herzegovina | Mirza Bašić | 167 | 12 | |
| Daniel Brands | 168 | 13 | ||
| Austria | Sebastian Ofner | 184 | 14 | |
 Kazakhstan | Aleksandr Nedovyesov | 185 | 15 | |
 Slovakia | Filip Horanský | 195 | 16 |
The following players received wildcards into the singles main draw:
The following player received entry into the singles main draw as an alternate:
Pavel KotovThe following players received entry into the singles main draw using their ITF World Tennis Ranking:
Andrés Artuñedo Baptiste Crepatte Grégoire Jacq Roman SafiullinThe following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
See main article: 2019 Open Harmonie mutuelle – Singles.
Kamil Majchrzak def. Maxime Janvier 6–3, 7–6(7–1).See main article: 2019 Open Harmonie mutuelle – Doubles.
Jonathan Erlich / Fabrice Martin def. Jonathan Eysseric / Antonio Šančić 7–6(7–2), 7–6(7–2).